Main content

    Health Information

    Vitamin A

    Vitamin A

    Uses

    What Are Star Ratings?

    Our proprietary ?Star-Rating? system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

    For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

    3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.

    2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

    1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

    This supplement has been used in connection with the following health conditions:

    Used for Why
    3 Stars
    Anemia
    10,000 to 25,000 IU daily
    Vitamin A deficiency can contribute to anemia, supplementing with this vitamin may restore levels and improve symptoms.

    Deficiencies of iron , vitamin B12 , and folic acid are the most common nutritional causes of anemia.1 Although rare, severe deficiencies of several other vitamins and minerals, including vitamin A ,2 , 3 vitamin B2 ,4 vitamin B6 ,5 , 6 vitamin C ,7 and copper ,8 , 9 can also cause anemia by various mechanisms. Rare genetic disorders can cause anemias that may improve with large amounts of supplements such as vitamin B1 .10 , 11

    3 Stars
    Childhood Diseases
    High doses of vitamin A may be used to treat measles or chicken pox, but only under a doctor's supervision
    Vitamin A plays a critical role in proper immune function, it has been used successfully to prevent and treat measles and to treat chicken pox.

    Preliminary research shows that supplemental vitamin A improves the likelihood that the measles vaccine will provide protection.12 Vitamin A has, since the 1920s, been the subject of much research into the prevention and treatment of childhood exanthems, particularly measles.13 This nutrient has a critical role in proper immune function , and there is evidence that supplementation with vitamin A reduces the incidence and severity of, and deaths from, childhood measles.14 , 15 The World Health Organization (WHO) has therefore recommended that children with signs of deficiency receive supplementation with vitamin A. The recommended amounts are 100,000 IU for children younger than one year and 200,000 IU for children older than one year, immediately upon diagnosis, and repeated once the next day and once in one to four weeks.16 A controlled trial of African children given vitamin A supplementation according to the WHO?s recommendations found that severity of measles and its long-term consequences were reduced by 82% on day eight, 61% in week six, and 85% six months after the onset.17

    Another controlled trial found that giving approximately 200,000 IU of vitamin A once during measles illness was not adequate to provide any benefit in African children whose vitamin A status was unknown.18 In a controlled prevention study, Indian children treated with 2,500 mcg (8,333 IU) of vitamin A weekly had fewer measles complications and less than half of the rate of death as compared with children receiving placebo;19 but in another study, Indian children receiving 200,000 IU of vitamin A every six months did not have a different rate of total infectious illness nor rate of death as compared with children receiving placebo.20

    An analysis of 20 controlled trials concluded that vitamin A supplementation reduced deaths from measles respiratory infection by 70%.21 While vitamin A deficiency is widespread in developing countries, it has also been reported in the United States and has been linked with more severe cases of measles.22 The American Academy of Pediatrics has recommended supplementation with vitamin A for children between the ages of six months and two years who are hospitalized with measles and its complications. The recommended amount is a single administration of 100,000 IU for children aged 6 to 12 months and 200,000 IU for children older than 1 year, followed by a second administration 24 hours later and a third after four weeks in children who are likely to have vitamin A deficiency.23

    One trial showed that low levels of vitamin A are more prevalent in children with measles than in similar children without measles, with levels rising back to normal several days after the onset of the infection. This observation led the authors of the study to conclude that vitamin A deficiency is a consequence of infection with the measles virus and to recommend supplementation with vitamin A during measles infection even when prior deficiency is not suspected.24 Vitamin A stores have also been shown to be depleted during chicken pox infection,25 and some preliminary data supports its use in treatment of chicken pox. In a controlled trial, in which children without vitamin A deficiency were given either 200,000 IU of vitamin A or placebo one time during chicken pox, the children given vitamin A had shorter duration of illness and fewer severe complications. The researchers then treated the patients? siblings with vitamin A before chicken pox became evident, and they had an even shorter length of illness.26

    3 Stars
    Cystic Fibrosis
    5,000 to 10,000 IU daily
    The fat malabsorption associated with cystic fibrosis often leads to a deficiency of fat-soluble vitamins, such as vitamin A. Supplementing with this vitamin can help counteract the deficiency.

    The fat malabsorption associated with CF often leads to a deficiency of fat-soluble vitamins. Oral supplementation of these nutrients is considered crucial to maintaining good nutritional status.27 Current recommendations for supplementation are as follows: vitamin A , 5,000 to 10,000 IU/day; vitamin D , 1,000 to 2,000 IU/day; vitamin E , 100 to 300 IU/day; and vitamin K , 5 mg every three days. Of the water-soluble vitamins, only vitamin B12 is poorly absorbed in cystic fibrosis,28 and taking pancreatic enzymes helps prevent B12 deficiencies.29

    3 Stars
    Infection
    See a doctor for evaluation of possible deficiency
    Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms.

    Nutrients useful for maintaining healthy immune function are also applicable for preventing infections. Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms.30 However, most research shows that while vitamin A supplementation helps people prevent or treat infections in developing countries where deficiencies are common,31 little to no positive effect, and even slight adverse effects, have resulted from giving vitamin A supplements to people in countries where most people consume adequate amounts of vitamin A.32 , 33 , 34 , 35 , 36 , 37 , 38 Moreover, vitamin A supplementation during infections appears beneficial only in certain diseases. An analysis of trials revealed that vitamin A reduces mortality from measles and diarrhea , but not from pneumonia, in children living in developing countries.39 A double-blind trial for vitamin A supplementation in Tanzanian children with pneumonia confirmed its lack of effectiveness for this condition.40 In general, parents in the developed world should not give vitamin A supplements to children unless there is a reason to believe vitamin A deficiency is likely, such as the presence of a condition causing malabsorption (e.g., celiac disease ). However, the American Academy of Pediatrics recommends that all children with measles should be given high-dose vitamin A for several days.

    3 Stars
    Leukoplakia
    28,500 IU daily under medical supervision
    Vitamin A has been shown to be effective against leukoplakia.

    Beta-carotene is the most widely used supplement in the treatment of leukoplakia. In a clinical trial of betel nut chewers with leukoplakia, supplementation with 150,000 IU of beta-carotene twice per week for six months significantly increased the remission rate compared with placebo (14.8% vs. 3.0%).41 The effectiveness of beta-carotene for treating leukoplakia was also confirmed in a double-blind trial that used 100,000 IU per day for six months.42 In one trial, supplementation with 33, 333 IU of beta-carotene per day, alone or combined with 50 IU of vitamin E , was reported not to reduce the incidence of leukoplakia.43 These results have also been observed in smaller trials.44 , 45

    Drug therapy with a synthetic, prescription form of vitamin A (known as Accutane®, isotretinoin , and 13-cis retinoic acid) has been reported to be more effective than treatment with 50,000 IU per day of beta-carotene.46 However, because of the potential toxicity of the vitamin A-like drug, it may be preferable to treat leukoplakia with beta-carotene, which is much safer.

    Before the research on beta-carotene was published, vitamin A was used to treat leukoplakia.47 One group of researchers reported that vitamin A (28,500 IU per day) was more effective than beta-carotene in treating people with leukoplakia.48 Another trial found that the combination of 150,000 IU per week of beta-carotene plus 100,000 IU per week of vitamin A led to a significant increase in remission time compared to beta carotene alone in betel nut chewers.49 Women who are or who could become pregnant should not take 100,000 IU of vitamin A per week without medical supervision.

    3 Stars
    Measles
    200,000 IU daily for two days under medical supervision
    In developing countries where vitamin A deficiency is common, preventive supplementation with vitamin A reduced the risk of death in children with measles.

    Measles appears to increase the body?s need for vitamin A .50 , 51 Studies in developing countries have shown that measles infection is more frequent and severe in people with low vitamin A blood levels,52 , 53 and preliminary research suggests this may also be true in the developed world.54 , 55 , 56 Repeatedly in controlled trials, preventive supplementation with vitamin A, at oral doses of up to 400,000 IU per day, reduced the risk of death in children with measles living in developing countries.57 , 58 , 59 Whether vitamin A supplementation would help people with measles in developed countries, where deficiency is uncommon, is less clear.60 However, the American Academy of Pediatrics recommends that all children with measles be given a short course of high-dose vitamin A. Two controlled studies of urban South African61 and Japanese62 children hospitalized with severe measles showed that supplementation with 100,000 to 400,000 IU of vitamin A resulted in faster recoveries, fewer complications, and fewer pneumonia-related deaths. An older study in England found one ounce per day of cod liver oil (containing about 40,000 IU of vitamin A, plus vitamin D and omega-3 fatty acids) reduced measles-related deaths in children hospitalized with severe cases of the disease.63 Such large doses of vitamin A should only be taken under a doctor?s supervision.

    3 Stars
    Night Blindness
    If deficient: 10,000 to 25,000 IU daily
    Night blindness may be an early sign of vitamin A deficiency. Doctors often recommend supplementing with vitamin A per day to correct a deficiency.

    Night blindness may be an early sign of vitamin A deficiency. Such a deficiency may result from diets low in animal foods (the main source of vitamin A), such as eggs, dairy products, organ meats, and some fish. Low intake of fruits and vegetables containing beta-carotene , which the body converts into vitamin A, may also contribute to a vitamin A deficiency. Doctors often recommend 10,000 to 25,000 IU of vitamin A per day to correct a deficiency. Beta-carotene is less effective at correcting vitamin A deficiency than is vitamin A itself, because it is not absorbed as well and is only slowly converted by the body into vitamin A.

    2 Stars
    Celiac Disease
    Consult a qualified healthcare practitioner
    Vitamin A deficiency may occur as a result of celiac disease, in which case vitamin A supplements or injections can be beneficial.

    In one study, six people with diet-treated celiac disease had abnormal dark-adaptation tests (indicative of ?night blindness?), even though some were taking a multivitamin that contained vitamin A . Some of these people showed an improvement in dark adaptation after receiving larger amounts of vitamin A, either orally or by injection.64 People with celiac disease should discuss the possibility of vitamin A deficiency with a healthcare practitioner before taking vitamin A supplements.

    2 Stars
    Heart Attack
    50,000 IU daily
    Taking vitamin A may reduce heart attack risk and may improve the outcome for people who have already had a heart attack.

    Blood levels of the antioxidant nutrients vitamins A, C, and E, and beta-carotene are reported to be lower in people with a history of heart attack, compared with healthy individuals.65 The number of free radical molecules is also higher, suggesting a need for antioxidants. Streptokinase, a drug therapy commonly used immediately following a heart attack, enhances the need for antioxidants.66

    Taking antioxidant supplements may improve the outcome for people who have already had a heart attack. In one double-blind trial, people were given 50,000 IU of vitamin A per day, 1,000 mg of vitamin C per day, 600 IU of vitamin E per day, and approximately 41,500 IU of beta-carotene per day or placebo.67 After 28 days, the infarct size of those receiving antioxidants was significantly smaller than the infarct size of the placebo group.

    Low levels of beta-carotene in fatty tissue have been linked to an increased incidence of heart attacks, particularly among smokers.68 One population study found that eating a diet high in beta-carotene is associated with a lower rate of nonfatal heart attacks.69 However, beta-carotene supplementation may not offer the same protection provided by foods that contain beta-carotene. Most,70 , 71 but not all, trials72 have found that supplemental beta-carotene is not associated with a reduced risk of heart attacks.

    2 Stars
    Immune Function
    Consult a qualified healthcare practitioner
    Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms.

    Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms.73 However, most research shows that while vitamin A supplementation helps people prevent or treat infections in developing countries where deficiencies are common,74 little to no positive effect, and even slight adverse effects, have resulted from giving vitamin A supplements to people in countries where most people consume adequate amounts of vitamin A.75 , 76 , 77 , 78 , 79 , 80 , 81 Moreover, vitamin A supplementation during infections appears beneficial only in certain diseases. An analysis of trials revealed that vitamin A reduces mortality from measles and diarrhea , but not from pneumonia, in children living in developing countries.82 A double-blind trial of vitamin A supplementation in Tanzanian children with pneumonia confirmed its lack of effectiveness for this condition.83 In general, parents in the developed world should not give vitamin A supplements to children unless there is a reason to believe vitamin A deficiency is likely, such as the presence of a condition causing malabsorption (e.g., celiac disease ). However, the American Academy of Pediatrics recommends that all children with measles be given short-term supplementation with high-dose vitamin A in cases of hospitalization, malnutrition, and other special circumstances determined by a doctor.84

    A combination of antioxidants vitamin A , vitamin C , and vitamin E significantly improved immune cell number and activity compared with placebo in a group of hospitalized elderly people.85 Daily intake of a 1,000 mg vitamin C plus 200 IU vitamin E for four months improved several measures of immune function in a preliminary study.86 To what extent immune-boosting combinations of antioxidants actually reduce the risk of infection remains unknown.

    2 Stars
    Iron-Deficiency Anemia (Iron)
    Consult a qualified healthcare practitioner
    Taking vitamin A and iron together has been reported to help overcome iron deficiency more effectively than iron supplements alone.

    Taking vitamin A and iron together has been reported to help overcome iron deficiency more effectively than iron supplements alone.87 Although the optimal amount of vitamin A needed to help people with iron deficiency has yet to be established, some doctors recommend 10,000 IU per day.

    2 Stars
    Menorrhagia
    50,000 IU of vitamin A each day taken under the supervision of a doctor
    In one study, women with menorrhagia who took vitamin A showed significant improvement or complete normalization of menstrual blood loss.

    In a study of women with menorrhagia who took 25,000 IU of vitamin A twice per day for 15 days, 93% showed significant improvement and 58% had a complete normalization of menstrual blood loss.88 However, women who are or could become pregnant should not supplement with more than 10,000 IU (3,000 mcg) per day of vitamin A.

    2 Stars
    Peptic Ulcer
    Take under medical supervision: 150,000 IU per day
    Vitamin A is needed to heal the linings of the stomach and intestines. In one trial, supplementing with vitamin A improved healing in a small group of people with stomach ulcer.

    Vitamin A is needed to heal the linings (called mucous membranes) of the stomach and intestines. In one controlled trial, vitamin A supplementation facilitated healing in a small group of people with stomach ulcer.89 The amount used in that study (150,000 IU per day) can be toxic and may also cause birth defects. Such a high dose should not be taken by a pregnant woman, by a woman who could become pregnant , or by anyone else without careful supervision from a doctor. Objective evidence of ulcer healing from taking vitamin A has been reported by the same research group.90 The effect of lower amounts of vitamin A has not been studied in people with peptic ulcer.

    2 Stars
    Severe Measles
    Consult a qualified healthcare practitioner
    Two studies of children with severe measles showed that supplementing with high doses vitamin A speeded recovery and reduced complications and pneumonia-related deaths.

    Vitamin A has a critical role in proper immune function , and evidence suggests that supplementing with it reduces the incidence and severity of, and deaths from, childhood measles.91 , 92 The World Health Organization (WHO) has therefore recommended that children with signs of deficiency receive supplementation with vitamin A. The recommended amounts are 100,000 IU for children younger than one year and 200,000 IU for children older than one year, immediately upon diagnosis, and repeated once the next day and once in one to four weeks.93 A controlled trial of African children given vitamin A supplementation according to the WHO?s recommendations found that severity of measles and its long-term consequences were reduced by 82% on day eight, 61% in week six, and 85% six months after the onset.94

    Another controlled trial found that giving approximately 200,000 IU of vitamin A once during measles illness was not adequate to provide any benefit in African children whose vitamin A status was unknown.95 In a controlled prevention study, Indian children treated with 2,500 mcg (8,333 IU) of vitamin A weekly had fewer measles complications and less than half of the rate of death as compared with children receiving placebo;96 but in another study, Indian children receiving 200,000 IU of vitamin A every six months did not have a different rate of total infectious illness nor rate of death as compared with children receiving placebo.97

    An analysis of 20 controlled trials concluded that vitamin A supplementation reduced deaths from measles respiratory infection by 70%.98 While vitamin A deficiency is widespread in developing countries, it has also been reported in the United States and has been linked with more severe cases of measles.99 The American Academy of Pediatrics has recommended supplementation with vitamin A for children between the ages of six months and two years who are hospitalized with measles and its complications. The recommended amount is a single administration of 100,000 IU for children aged 6 to 12 months and 200,000 IU for children older than 1 year, followed by a second administration 24 hours later and a third after four weeks in children who are likely to have vitamin A deficiency.100

    One trial showed that low levels of vitamin A are more prevalent in children with measles than in similar children without measles, with levels rising back to normal several days after the onset of the infection. This observation led the authors of the study to conclude that vitamin A deficiency is a consequence of infection with the measles virus and to recommend supplementation with vitamin A during measles infection even when prior deficiency is not suspected.101 Vitamin A stores have also been shown to be depleted during chicken pox infection,102 and some preliminary data supports its use in treatment of chicken pox. In a controlled trial, in which children without vitamin A deficiency were given either 200,000 IU of vitamin A or placebo one time during chicken pox, the children given vitamin A had shorter duration of illness and fewer severe complications. The researchers then treated the patients? siblings with vitamin A before chicken pox became evident, and they had an even shorter length of illness.103

    2 Stars
    Wound Healing
    Take under medical supervision: 25,000 IU daily
    Vitamin A plays a central role in wound healing and may be useful as a supplement or in a topical ointment.

    Vitamin A plays a central role in wound healing,104 but the effect of supplemental vitamin A in people who have suffered a minor injury and are not vitamin A-deficient remains unclear. Vitamin A supplements have been shown to improve healing in animal studies,105 and may be especially useful in a topical ointment for skin injuries in people taking corticosteroid medications.106 Although there are no studies in humans, some doctors recommend 25,000 IU of vitamin A per day, beginning two weeks prior to surgery and continuing for four weeks after surgery.

    1 Star
    Abnormal Pap Smear
    Refer to label instructions
    Women who don?t get enough vitamin A have an increased risk of cervical dysplasia, though there is little research on using vitamin A as a treatment.

    Women with a low intake of vitamin A have an increased risk of cervical dysplasia.107 However, there is little research on the use of vitamin A as a treatment for cervical dysplasia.

    1 Star
    Acne Vulgaris
    Refer to label instructions
    Under medical supervision, large quantities of vitamin A have been used successfully to treat severe acne. However, the acne typically returns after treatment is discontinued.

    Large quantities of vitamin A ?such as 300,000 IU per day for females and 400,000?500,000 IU per day for males?have been used successfully to treat severe acne.108 However, unlike the long-lasting benefits of the synthetic prescription version of vitamin A ( isotretinoin as Accutane), the acne typically returns several months after natural vitamin A is discontinued. In addition, the large amounts of vitamin A needed to control acne can be toxic and should be used only under careful medical supervision.

    1 Star
    Alcohol Withdrawal
    Refer to label instructions
    Because of potential liver damage, correcting the vitamin A deficiency common to alcoholics requires a doctor?s supervision to monitor liver function.

    Although the incidence of B-complex deficiencies is known to be high in alcoholics, the incidence of other vitamin deficiencies remains less clear.109 Nonetheless, deficiencies of vitamin A , vitamin D , vitamin E , and vitamin C are seen in many alcoholics. While some reports have suggested it may be safer for alcoholics to supplement with beta-carotene instead of vitamin A,110 potential problems accompany the use of either vitamin A or beta-carotene in correcting the deficiency induced by alcoholism.111 These problems result in part because the combinations of alcohol and vitamin A or alcohol and beta-carotene appear to increase potential damage to the liver. Thus, vitamin A-depleted alcoholics require a doctor?s intervention, including supplementation with vitamin A and beta-carotene accompanied by assessment of liver function. Supplementing with vitamin C, on the other hand, appears to help the body rid itself of alcohol.112 Some doctors recommend 1 to 3 grams per day of vitamin C.

    1 Star
    Conjunctivitis and Blepharitis
    Refer to label instructions
    Vitamin A deficiency has been reported in people with chronic conjunctivitis, but it is unknown whether vitamin A supplementation can help the condition.

    Vitamin A deficiency has been reported in people with chronic conjunctivitis.113 It is unknown whether vitamin A supplementation can prevent conjunctivitis or help people who already have the condition.

    1 Star
    Crohn?s Disease
    Refer to label instructions
    Vitamin A is needed for the growth and repair of cells that line both the small and large intestine and can improve symptoms in people with Crohn?s disease.

    Vitamin A is needed for the growth and repair of cells that line both the small and large intestine.114 At least two case reports describe people with Crohn?s disease who have responded to vitamin A supplementation.115 , 116 However, in one trial, vitamin A supplementation failed to maintain remission of the disease.117 Therefore, although some doctors recommend 50,000 IU per day for adults with Crohn?s disease, this approach remains unproven. An amount this high should never be taken without qualified guidance, nor should it be given to a woman who is or could become pregnant .

    1 Star
    Diarrhea
    Refer to label instructions
    Only in cases of malabsorption should vitamin A be used to treat diarrhea, as it has been shown to have no effect or to increase risk of diarrhea in well-nourished children.

    It is known vitamin A supplements support immune function and prevent infections. This is true, however, only under some circumstances. Vitamin A supplementation can also increase the risk of infections, according to the findings of a double-blind trial.118 In a study of African children between six months and five years old, a 44% reduction in the risk of severe diarrhea was seen in those children given four 100,000?200,000 IU supplements of vitamin A (the lower amount for those less than a year old) during an eight-month period. On further investigation, the researchers discovered that the reduction in diarrhea occurred only in children who were very malnourished. For children who were not starving, vitamin A supplementation actually increased the risk of diarrhea compared with the placebo group. The vitamin A-supplemented children also had a 67% increased risk of coughing and rapid breathing, and signs of further lung infection, although this problem did not appear in children infected with the AIDS virus. These findings should be of concern to American parents, whose children are not usually infected with HIV or severely malnourished. Such relatively healthy children fared poorly in the African trial in terms of both the risk of diarrhea and the risk of continued lung problems. Vitamin A provided no benefit to the well-nourished kids. Therefore, it makes sense not to give vitamin A supplements to children unless there is a special reason to do so, such as the presence of a condition causing malabsorption (e.g., celiac disease ).

    1 Star
    Gastritis
    Refer to label instructions
    Vitamin A appears to reduce ulcer size and pain in people with ulcers and may help treat gastritis.

    Zinc and vitamin A , nutrients that aid in healing, are commonly used to help people with peptic ulcers. For example, the ulcers of people taking 50 mg of zinc three times per day healed three times faster than those of people who took placebo.119 Since some types of gastritis can progress to peptic ulcer, it is possible that taking it may be useful. Nevertheless, the research does not yet show that zinc specifically helps people with gastritis. The amount of zinc used in this study is very high compared with what most people take (15?40 mg per day). Even at these lower levels, it is necessary to take 1?3 mg of copper per day to avoid a zinc-induced copper deficiency.

    1 Star
    Goiter
    Refer to label instructions
    Vitamin A levels are lower in people with goiter than in those without. A combination of vitamin C, vitamin E, and beta-carotene prevented goiter formation in iodine-deficient conditions in some research.

    Blood levels of vitamin A are lower in people with goiter than in similar people without goiter.120 , 121 The same relationship has been found for vitamin E and goiter.122 Animal research has found that, in iodine-deficient conditions, a supplement combination of vitamin C , vitamin E, and beta-carotene prevented goiter formation (though hypothyroidism was not improved), and vitamin E alone had a similar effect.123 No studies have been done to investigate this benefit in humans.

    1 Star
    HIV and AIDS Support
    Refer to label instructions
    Vitamin A deficiency is common in people with HIV infection, and low levels of the vitamin are associated with greater disease severity. Ask your doctor if vitamin A is right for you.

    Vitamin A deficiency appears to be very common in people with HIV infection. Low blood levels of vitamin A are associated with greater disease severity124 and increased transmission of the virus from a pregnant mother to her infant.125 However, in preliminary 126 and double-blind127 , 128 trials, supplementation with vitamin A failed to reduce the overall mother-to-child transmission of HIV. HIV-positive women who took 5,000 IU per day of vitamin A (as retinyl palmitate) and 50,000 IU per day of beta-carotene during the third trimester (13 weeks) of pregnancy, plus an additional single amount of 200,000 IU of vitamin A at delivery, had the same rate of transmission of HIV to their infants as those who did not take the supplement. However, lower rates of illness have been observed in the children of HIV-positive mothers when the children were supplemented with 50,000?200,000 IU of vitamin A every two to three months.129

    Little research has explored whether vitamin A supplements are helpful at halting disease progression. HIV-positive children given two consecutive oral supplements of vitamin A (200,000 IU in a gelcap) in the two days following influenza vaccinations had a modest but significant decrease in viral load.130 In one trial, giving people an extremely high (300,000 IU) amount of vitamin A one time only did not improve short-term measures of immunity in women with HIV.131

    1 Star
    Hypothyroidism
    Refer to label instructions
    People with hypothyroidism may have an impaired ability to convert beta-carotene to vitamin A. For this reason, some doctors suggest supplementing with vitamin A.

    People with hypothyroidism have been shown to have an impaired ability to convert beta-carotene to vitamin A .132 , 133 For this reason, some doctors suggest taking supplemental vitamin A (approximately 5,000?10,000 IU per day) if they are not consuming adequate amounts in their diet.

    1 Star
    Pre- and Post-Surgery Health
    Refer to label instructions
    Topical vitamin A may help speed wound healing and reduce scarring in patients taking corticosteroids, which typically slow wound healing.

    Vitamin A plays an important role in wound healing ,134 and one animal study suggests that vitamin A deficiency might contribute to poor recovery after surgery.135 Vitamin A may be particularly beneficial to post-surgical patients who are using corticosteroid medications. These medications typically slow wound healing, and a number of animal studies have found that both topical and oral vitamin A reverse this effect; however, vitamin A does not change healing time in animals not given corticosteroids.136 , 137 , 138 Similar results have been reported for topical vitamin A in some human cases, and these researchers suggest a topical preparation containing 200,000 IU of vitamin A per ounce for improved surgical wound healing in patients using corticosteroids after surgery.139 Topical vitamin A may also reduce scarring in patients taking corticosteroids.140

    1 Star
    Premenstrual Syndrome
    Refer to label instructions
    Very high amounts of vitamin A have reduced PMS symptoms in some studies.

    Very high amounts of vitamin A?100,000 IU per day or more?have reduced symptoms of PMS,141 , 142 but such an amount can cause serious side effects with long-term use. Women who are or who could become pregnant should not supplement with more than 10,000 IU (3,000 mcg) per day of vitamin A. Other people should not take more than 25,000 IU per day without the supervision of their doctor. As yet, no trials have explored the effects of these safer amounts of vitamin A in women suffering from PMS.

    1 Star
    Sickle Cell Anemia
    Refer to label instructions
    Sickle cell anemia patients tend to have low levels of antioxidants, which protect cells from oxygen-related damage. Supplementing with vitamin A may help correct a deficiency.

    Antioxidant nutrients protect the body?s cells from oxygen-related damage. Many studies show that sickle cell anemia patients tend to have low blood levels of antioxidants, including carotenoids , vitamin A , vitamin E , and vitamin C , despite adequate intake.143 , 144 , 145 , 146 , 147 , 148 Low blood levels of vitamin E in particular have been associated with higher numbers of diseased cells in children149 and with greater frequency of symptoms in adults.150 A small, preliminary trial reported a 44% decrease in the average number of diseased cells in six sickle cell anemia patients given 450 IU vitamin E per day for up to 35 weeks. This effect was maintained as long as supplementation continued.151

    1 Star
    Type 1 Diabetes (Selenium, Vitamin C, Vitamin E)
    Refer to label instructions
    A combination of the antioxidants selenium, vitamin A, vitamin C, and vitamin E has been shown to improve diabetic retinopathy.
    Because oxidation damage is believed to play a role in the development of diabetic eye damage ( retinopathy ), antioxidant nutrients might be protective. One doctor has administered a daily regimen of 500 mcg selenium , 800 IU vitamin E , 10,000 IU vitamin A , and 1,000 mg vitamin C for several years to 20 people with diabetic eye damage ( retinopathy ). During that time, 19 of the 20 people showed either improvement or no progression of their retinopathy.152 People who wish to supplement with more than 250 mcg of selenium per day should consult a healthcare practitioner.
    1 Star
    Type 1 Diabetes and Diabetic Retinopathy (Selenium, Vitamin C, Vitamin E)
    Refer to label instructions
    Antioxidant nutrients including selenium, vitamin A, vitamin C, and vitamin E may combat free radicals associated with diabetic retinopathy.
    Because oxidation damage is believed to play a role in the development of diabetic eye damage ( retinopathy ), antioxidant nutrients might be protective. One doctor has administered a daily regimen of 500 mcg selenium , 800 IU vitamin E , 10,000 IU vitamin A , and 1,000 mg vitamin C for several years to 20 people with diabetic eye damage ( retinopathy ). During that time, 19 of the 20 people showed either improvement or no progression of their retinopathy.153 People who wish to supplement with more than 250 mcg of selenium per day should consult a healthcare practitioner.
    1 Star
    Urinary Tract Infection
    Refer to label instructions
    Vitamin A deficiency increases the risk of many infection, supplementing with it may restore levels and help support the immune system.

    Vitamin A deficiency increases the risk of many infections. Although much of the promising research with vitamin A supplements and infections has focused on measles,154 vitamin A is also thought to be helpful in other infections. Some doctors recommend that people with urinary tract infections take vitamin A. A typical amount recommended to correct a deficiency is 10,000 to 25,000 IU per day.

    1 Star
    Vaginitis
    Refer to label instructions
    Some doctors recommend vaginal administration of vitamin A to improve the integrity of the vaginal tissue and to enhance the function of local immune cells.

    Some doctors recommend vitamin E (taken orally, topically, or vaginally) for certain types of vaginitis. Vitamin E as a suppository in the vagina or vitamin E oil can be used once or twice per day for 3 to 14 days to soothe the mucous membranes of the vagina and vulva. Some doctors recommend vaginal administration of vitamin A to improve the integrity of the vaginal tissue and to enhance the function of local immune cells. Vitamin A can be administered vaginally by inserting a vitamin A capsule or using a prepared vitamin A suppository. Vitamin A used this way can be irritating to local tissue, so it should not be used more than once per day for up to seven consecutive days.

    0 Stars
    Sunburn (Vitamin E)
    Refer to label instructions

    Antioxidants may protect the skin from sunburn due to free radical ?producing ultraviolet rays.155 Combinations of 1,000 to 2,000 IU per day of vitamin E and 2,000 to 3,000 mg per day of vitamin C , but neither given alone, have a significant protective effect against ultraviolet rays, according to double-blind studies.156 , 157 , 158

    Oral synthetic beta-carotene alone was not found to provide effective protection when given in amounts of 15 mg per day or for only a few weeks? time in larger amounts of 60 to 90 mg per day, but it has been effective either in very large (180 mg per day) amounts or in smaller amounts (30 mg per day) in combination with topical sunscreen.159 , 160 , 161 , 162 , 163

    Natural sources of beta-carotene or other carotenoids have been more consistently shown to protect against sunburn. One controlled study found that taking a supplement of natural carotenoids (almost all of which was beta-carotene) in daily amounts of 30 mg, 60 mg, and 90 mg gave progressively more protection against ultraviolet rays.164 In another controlled study, either 24 mg per day of natural beta-carotene or 24 mg per day of a carotenoid combination of equal amounts beta-carotene, lutein , and lycopene helped protect skin from ultraviolet rays.165 A preliminary study compared synthetic lycopene (10.1 mg per day), a natural tomato extract containing 9.8 mg of lycopene per day plus additional amounts of other carotenoids, and a solubilized tomato drink (designed to increase lycopene absorption) containing 8.2 mg of lycopene plus additional amounts of other carotenoids. After 12 weeks, only the two tomato-based products were shown to give significant protection against burning by ultraviolet light.166

    Still other trials have tested combinations of several antioxidants . One preliminary study found that a daily combination of beta-carotene (6 mg), lycopene (6 mg), vitamin E (15 IU), and selenium for seven weeks protected against ultraviolet light.167 However, a double-blind trial of a combination of smaller amounts of several carotenoids , vitamins C and E, selenium, and proanthocyanidins did not find significant UV protection compared with placebo.168 Similarly, in a controlled trial, a combination of selenium, copper , and vitamins was found to be ineffective.169

    It should be noted that while oral protection from sunburn has been demonstrated with several types of antioxidants , the degree of protection (typically less than an SPF of 2) is much less than that provided by currently available topical sunscreens. On the other hand, these modest effects will provide some added protection to skin areas where sunscreen is also used and will give a small amount of protection to sun-exposed areas where sunscreen is not applied. However, oral protection from sunburn is not instantaneous; maximum effects are not reached until these antioxidants have been used for about eight to ten weeks.170 , 171

    0 Stars
    Sunburn (Vitamin D)
    Refer to label instructions

    Antioxidants may protect the skin from sunburn due to free radical ?producing ultraviolet rays.172 Combinations of 1,000 to 2,000 IU per day of vitamin E and 2,000 to 3,000 mg per day of vitamin C , but neither given alone, have a significant protective effect against ultraviolet rays, according to double-blind studies.173 , 174 , 175

    Oral synthetic beta-carotene alone was not found to provide effective protection when given in amounts of 15 mg per day or for only a few weeks? time in larger amounts of 60 to 90 mg per day, but it has been effective either in very large (180 mg per day) amounts or in smaller amounts (30 mg per day) in combination with topical sunscreen.176 , 177 , 178 , 179 , 180

    Natural sources of beta-carotene or other carotenoids have been more consistently shown to protect against sunburn. One controlled study found that taking a supplement of natural carotenoids (almost all of which was beta-carotene) in daily amounts of 30 mg, 60 mg, and 90 mg gave progressively more protection against ultraviolet rays.181 In another controlled study, either 24 mg per day of natural beta-carotene or 24 mg per day of a carotenoid combination of equal amounts beta-carotene, lutein , and lycopene helped protect skin from ultraviolet rays.182 A preliminary study compared synthetic lycopene (10.1 mg per day), a natural tomato extract containing 9.8 mg of lycopene per day plus additional amounts of other carotenoids, and a solubilized tomato drink (designed to increase lycopene absorption) containing 8.2 mg of lycopene plus additional amounts of other carotenoids. After 12 weeks, only the two tomato-based products were shown to give significant protection against burning by ultraviolet light.183

    Still other trials have tested combinations of several antioxidants . One preliminary study found that a daily combination of beta-carotene (6 mg), lycopene (6 mg), vitamin E (15 IU), and selenium for seven weeks protected against ultraviolet light.184 However, a double-blind trial of a combination of smaller amounts of several carotenoids , vitamins C and E, selenium, and proanthocyanidins did not find significant UV protection compared with placebo.185 Similarly, in a controlled trial, a combination of selenium, copper , and vitamins was found to be ineffective.186

    It should be noted that while oral protection from sunburn has been demonstrated with several types of antioxidants , the degree of protection (typically less than an SPF of 2) is much less than that provided by currently available topical sunscreens. On the other hand, these modest effects will provide some added protection to skin areas where sunscreen is also used and will give a small amount of protection to sun-exposed areas where sunscreen is not applied. However, oral protection from sunburn is not instantaneous; maximum effects are not reached until these antioxidants have been used for about eight to ten weeks.187 , 188

    How It Works

    How to Use It

    For most people, up to 25,000 IU (7,500 mcg) of vitamin A per day is considered safe. However, people over age 65 and those with liver disease should probably not supplement with more than 15,000 IU per day, unless supervised by a doctor. In women who could become pregnant , the maximum safe intake is being re-evaluated. However, less than 10,000 IU (3,000 mcg) per day is generally accepted as safe. There is concern that larger intakes could cause birth defects . Whether the average person would benefit from vitamin A supplementation remains unclear.

    Where to Find It

    Liver, dairy products, and cod liver oil are good sources of vitamin A. Vitamin A is also available in supplement form.

    Possible Deficiencies

    People who limit their consumption of liver, dairy foods, and beta-carotene -containing vegetables can develop a vitamin A deficiency. Extremely low birth weight babies (2.2 pounds or less) are at high risk of being born with a deficiency, and vitamin A shots given to these infants have been reported in double-blind research to reduce the risk of lung disease.189 The earliest deficiency sign is poor night vision . Deficiency symptoms can also include dry skin, increased risk of infections , and metaplasia (a precancerous condition). Severe deficiencies causing blindness are extremely rare in Western societies.

    Less severe deficiencies are more likely to occur with a variety of conditions causing malabsorption . A high incidence of vitamin A deficiency in people infected with HIV has also been reported. People with hypothyroidism have an impaired ability to convert beta-carotene to vitamin A.190 , 191 For this reason, some doctors suggest taking supplemental vitamin A (perhaps 5,000?10,000 IU per day) if they are not consuming adequate amounts in their diet.

    Very old people with type 2 diabetes have shown a significant age-related decline in blood levels of vitamin A, irrespective of their dietary intake.192

    Interactions

    Interactions with Supplements, Foods, & Other Compounds

    Taking vitamin A and iron together helps overcome iron deficiency more effectively than iron supplementation alone.193 Supplementation with zinc , iron, or the combination has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients.194

    Interactions with Medicines

    Certain medicines interact with this supplement.

    Types of interactions: Beneficial Adverse Check

    Replenish Depleted Nutrients

    • Carbamazepine

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.201 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Cholestyramine

      Bile acid sequestrants may prevent absorption of folic acid and the fat-soluble vitamins A , D , E , and K .220 , 221 Other medications and vitamin supplements should be taken one hour before or four to six hours after bile acid sequestrants for optimal absorption.222 Animal studies suggest calcium and zinc may also be depleted by taking cholestyramine.223

    • Colesevelam

      Bile acid sequestrants may prevent absorption of folic acid and the fat-soluble vitamins A , D , E , and K .230 , 231 Other medications and vitamin supplements should be taken one hour before or four to six hours after bile acid sequestrants for optimal absorption.232 Animal studies suggest calcium and zinc may also be depleted by taking cholestyramine.233

    • Colestipol

      Bile acid sequestrants, including colestipol, may prevent absorption of folic acid and the fat-soluble vitamins A , D , E , K .234 , 235 People taking colestipol should consult with their doctor about vitamin malabsorption and supplementation. People should take other drugs and vitamin supplements one hour before or four to six hours after colestipol to improve absorption.236

      Animal studies suggest calcium and zinc may be depleted by taking cholestyramine, another bile acid sequestrant. 237 Whether these same interactions would occur with colestipol is not known.

    • Felbamate

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.251 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Gabapentin

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.264 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Levetiracetam

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.277 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Mineral Oil

      Mineral oil has interfered with the absorption of many nutrients, including beta-carotene , calcium , phosphorus , potassium , and vitamins A , D , K , and E in some,302 but not all,303 research. Taking mineral oil on an empty stomach may reduce this interference. It makes sense to take a daily multivitamin-mineral supplement two hours before or after mineral oil. It is important to read labels, because many multivitamins do not contain vitamin K or contain inadequate (less than 100 mcg per day) amounts.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Neomycin

      Neomycin can decrease absorption or increase elimination of many nutrients, including calcium , carbohydrates, beta-carotene , fats, folic acid , iron , magnesium , potassium , sodium, and vitamin A , vitamin B12 , vitamin D , and vitamin K .304 , 305 Surgery preparation with oral neomycin is unlikely to lead to deficiencies. It makes sense for people taking neomycin for more than a few days to also take a multivitamin-mineral supplement.

    • Orlistat

      In one well-controlled study, taking orlistat for six months resulted in reduced blood levels of vitamins A and D, though levels for most individuals remained within the normal range. However, a few people developed levels low enough to require supplementation.306 Other studies have shown that taking orlistat had no affect on blood vitamin A levels.307 , 308 Although additional research is needed, the current evidence suggests that individuals taking orlistat for more than six months should supplement with vitamins A and D.

    • Oxcarbazepine

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.309 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Phenobarbital

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.310 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Phenytoin

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.311 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Thioridazine

      A review of people taking thioridazine showed that they had higher blood levels of vitamin A than did individuals not using the drug.327 More research is necessary to determine whether taking vitamin A supplements with thioridazine might cause dangerously high vitamin A levels. Until more is known, people taking thioridazine should exercise caution with vitamin A supplementation and be alert for side effects such as bone pain, headaches, dry scaly skin, and hair loss.

    • Topiramate

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.334 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    • Valproate

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.341 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Zonisamide

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.348 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

    Reduce Side Effects

    • Busulfan

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.195 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.196 Vitamin C appears to increase the effectiveness of chemotherapy in animals197 and with human breast cancer cells in test tube research.198 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.199

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.200 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Carboplatin

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.202 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.203 Vitamin C appears to increase the effectiveness of chemotherapy in animals204 and with human breast cancer cells in test tube research.205 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.206

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.207 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

    • Carmustine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.208 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.209 Vitamin C appears to increase the effectiveness of chemotherapy in animals210 and with human breast cancer cells in test tube research.211 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.212

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.213 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Chlorambucil

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.214 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.215 Vitamin C appears to increase the effectiveness of chemotherapy in animals216 and with human breast cancer cells in test tube research.217 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.218

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.219 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Cladribine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.224 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.225 Vitamin C appears to increase the effectiveness of chemotherapy in animals226 and with human breast cancer cells in test tube research.227 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.228

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.229 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Erlotinib

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.245 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.246 Vitamin C appears to increase the effectiveness of chemotherapy in animals247 and with human breast cancer cells in test tube research.248 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.249

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.250 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Floxuridine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.252 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.253 Vitamin C appears to increase the effectiveness of chemotherapy in animals254 and with human breast cancer cells in test tube research.255 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.256

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.257 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Fludarabine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.258 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.259 Vitamin C appears to increase the effectiveness of chemotherapy in animals260 and with human breast cancer cells in test tube research.261 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.262

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.263 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Ifosfamide

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.265 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.266 Vitamin C appears to increase the effectiveness of chemotherapy in animals267 and with human breast cancer cells in test tube research.268 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.269

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.270 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Irinotecan

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.271 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.272 Vitamin C appears to increase the effectiveness of chemotherapy in animals273 and with human breast cancer cells in test tube research.274 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.275

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.276 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Lomustine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.278 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.279 Vitamin C appears to increase the effectiveness of chemotherapy in animals280 and with human breast cancer cells in test tube research.281 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.282

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.283 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Mechlorethamine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.284 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.285 Vitamin C appears to increase the effectiveness of chemotherapy in animals286 and with human breast cancer cells in test tube research.287 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.288

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.289 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Melphalan

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.290 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.291 Vitamin C appears to increase the effectiveness of chemotherapy in animals292 and with human breast cancer cells in test tube research.293 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.294

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.295 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

    • Mercaptopurine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.296 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.297 Vitamin C appears to increase the effectiveness of chemotherapy in animals298 and with human breast cancer cells in test tube research.299 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.300

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.301 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Polifeprosan 20 with Carmustine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.312 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.313 Vitamin C appears to increase the effectiveness of chemotherapy in animals314 and with human breast cancer cells in test tube research.315 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.316

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.317 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Prednisolone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.318 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy319?most likely due to mobilization of the vitamin from its stores in the liver evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.320

    • Thioguanine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.321 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.322 Vitamin C appears to increase the effectiveness of chemotherapy in animals323 and with human breast cancer cells in test tube research.324 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.325

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.326 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Thiotepa

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.328 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.329 Vitamin C appears to increase the effectiveness of chemotherapy in animals330 and with human breast cancer cells in test tube research.331 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.332

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.333 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Uracil Mustard

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.335 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.336 Vitamin C appears to increase the effectiveness of chemotherapy in animals337 and with human breast cancer cells in test tube research.338 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.339

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.340 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Vincristine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.342 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.343 Vitamin C appears to increase the effectiveness of chemotherapy in animals344 and with human breast cancer cells in test tube research.345 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.346

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.347 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

    Support Medicine

    • Docetaxel

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.238 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.239 Vitamin C appears to increase the effectiveness of chemotherapy in animals240 and with human breast cancer cells in test tube research.241 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.242

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but it clearly shows that antioxidants need not be avoided for fear that the actions of chemotherapy are interfered with.243 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      A new formulation of selenium (Seleno-Kappacarrageenan) was found to reduce kidney damage and white blood cell?lowering effects of cisplatin in one human study. However, the level used in this study (4,000 mcg per day) is potentially toxic and should only be used under the supervision of a doctor.244

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

    Reduces Effectiveness

    • none

    Potential Negative Interaction

    • Atorvastatin

      A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found blood vitamin A levels increased over two years of therapy.349 Until more is known, people taking HMG-CoA reductase inhibitors, including atorvastatin, should have blood levels of vitamin A monitored if they intend to supplement vitamin A.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Isotretinoin

      Although little is known about how isotretinoin interacts with real vitamin A, the two are structurally similar and have similar toxicities. Therefore, people taking isotretinoin should avoid vitamin A supplements at levels higher than typically found in a multivitamin (10,000 IU per day).

    • Minocycline

      A 16-year-old girl developed headaches and double vision following treatment for acne with vitamin A and minocycline. These side effects disappeared once the compounds were discontinued.350 More research is needed to determine whether the symptoms could have been caused by an interaction between vitamin A and the drug.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Tretinoin

      Large amounts of vitamin A can cause side effects, and oral tretinoin can cause similar side effects. Combining vitamin A with oral tretinoin is likely to increase the risk of side effects. People taking oral tretinoin should probably not take more than 10,000 IU of supplemental vitamin A per day.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

    Explanation Required

    • Busulfan

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.351 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Capecitabine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.358 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Carboplatin

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.359 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Carmustine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.360 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Chlorambucil

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.361 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Cisplatin

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.362 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.363 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.364 Vitamin C appears to increase the effectiveness of chemotherapy in animals365 and with human breast cancer cells in test tube research.366 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.367

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.368 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Cladribine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.369 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Cortisone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.370 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy371?most likely due to mobilization of the vitamin from its stores in the liver?evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.372

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Cyclophosphamide

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.373 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Cytarabine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.375 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.376 Vitamin C appears to increase the effectiveness of chemotherapy in animals377 and with human breast cancer cells in test tube research.378 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.379

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.380 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Desogestrel-Ethinyl Estradiol

      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.381 , 382 , 383 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .384 , 385 , 386 Oral contraceptives may interfere with manganese absorption.387 The clinical importance of these actions remains unclear.

    • Dexamethasone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.388 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy389?most likely due to mobilization of the vitamin from its stores in the liver?evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.390

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Docetaxel

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.391 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Erlotinib

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.392 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Ethinyl Estradiol and Levonorgestrel
      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.393 , 394 , 395 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .396 , 397 , 398 Oral contraceptives may interfere with manganese absorption.399 The clinical importance of these actions remains unclear.
    • Ethinyl Estradiol and Norethindrone

      A review of literature suggests that women who use OCs may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.400 , 401 , 402 OC use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .403 , 404 , 405 OCs may interfere with manganese absorption.406 The clinical importance of these actions remains unclear.

    • Ethinyl Estradiol and Norgestrel

      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.407 , 408 , 409 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .410 , 411 , 412 Oral contraceptives may interfere with manganese absorption.413 The clinical importance of these actions remains unclear.

    • Etoposide

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.415 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.416 Vitamin C appears to increase the effectiveness of chemotherapy in animals417 and with human breast cancer cells in test tube research.418 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.419

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.420 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Floxuridine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.421 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Fludarabine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.422 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Fluorouracil

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.424 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.425 Vitamin C appears to increase the effectiveness of chemotherapy in animals426 and with human breast cancer cells in test tube research.427 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.428

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but the article strongly suggests that antioxidants need not be avoided for fear that the actions of chemotherapy would be interfered with.429

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Fluvastatin

      A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found blood vitamin A levels increased during two years of therapy.430 Until more is known, people taking HMG-CoA reductase inhibitors, including fluvastatin, should have blood levels of vitamin A monitored if they intend to supplement vitamin A.

    • Hydroxyurea

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.432 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.433 Vitamin C appears to increase the effectiveness of chemotherapy in animals434 and with human breast cancer cells in test tube research.435 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.436

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.437 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Ifosfamide

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.438 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Irinotecan

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.439 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Levonorgestrel

      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.440 , 441 , 442 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .443 , 444 , 445 Oral contraceptives may interfere with manganese absorption.446 The clinical importance of these actions remains unclear.

    • Levonorgestrel-Ethinyl Estrad

      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.447 , 448 , 449 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .450 , 451 , 452 Oral contraceptives may interfere with manganese absorption.453 The clinical importance of these actions remains unclear.

    • Lomustine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.454 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Lovastatin

      A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found serum vitamin A levels increased over two years of therapy.455 It remains unclear whether this moderate increase should suggest that people taking lovastatin have a particular need to restrict vitamin A supplementation.

    • Mechlorethamine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.456 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Medroxyprogesterone

      In a one-year study of predominantly malnourished women in India and Thailand, medroxyprogesterone used for contraception was associated with increased blood levels of vitamin A and folic acid.457 The clinical meaning of these changes remains unclear.

    • Melphalan

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.458 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Mercaptopurine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.459 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Mestranol and Norethindrone

      A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.460 , 461 , 462 Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .463 , 464 , 465 Oral contraceptives may interfere with manganese absorption.466 The clinical importance of these actions remains unclear.

    • Methylprednisolone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.467 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy468?most likely due to mobilization of the vitamin from its stores in the liver?evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.469

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Norgestimate-Ethinyl Estradiol

      A review of literature suggests that women who use OCs may experience decreased vitamin B1 , B2 , B3 , B12 , C , and zinc levels.470 , 471 , 472 OC use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A .473 , 474 , 475 OCs may interfere with manganese absorption.476 The clinical importance of these actions remains unclear.

    • Paclitaxel

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.477 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.478 Vitamin C appears to increase the effectiveness of chemotherapy in animals479 and with human breast cancer cells in test tube research.480 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.481

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but the article strongly suggests that antioxidants need not be avoided for fear that the actions of chemotherapy would be interfered with.482

      A new formulation of selenium (Seleno-Kappacarrageenan) was found to reduce kidney damage and white blood cell?lowering effects of cisplatin in one human study. However, the level used in this study (4,000 mcg per day) is potentially toxic and should only be used under the supervision of a doctor.483

      Glutathione , the main antioxidant found within cells, is frequently depleted in individuals on chemotherapy and/or radiation. Preliminary studies have found that intravenously injected glutathione may decrease some of the adverse effects of chemotherapy and radiation, such as diarrhea .484

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Polifeprosan 20 with Carmustine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.485 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Pravastatin

      A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found serum vitamin A levels increased over two years of therapy.486 It remains unclear whether this moderate increase suggests that people taking lovastatin have a particular need to restrict vitamin A supplementation.

    • Prednisolone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.487 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy488?most likely due to mobilization of the vitamin from its stores in the liver evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.489

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Prednisone

      In some people, treatment with corticosteroids can impair wound healing . In one study, topical or internal vitamin A improved wound healing in eight of ten patients on corticosteroid therapy.490 In theory, vitamin A might also reverse some of the beneficial effects of corticosteroids, but this idea has not been investigated and no reports exist of such an interaction in people taking both vitamin A and corticosteroids. People using oral corticosteroids should consult with a doctor to determine whether improved wound healing might outweigh the theoretical risk associated with concomitant vitamin A use.

      Although blood levels of vitamin A appear to increase during dexamethasone therapy491?most likely due to mobilization of the vitamin from its stores in the liver?evidence from animal studies has also indicated that corticosteroids can deplete vitamin A from tissues.492

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Primidone

      Anticonvulsant drugs can occasionally cause birth defects when taken by pregnant women, and their toxicity might be related to low blood levels of vitamin A. One controlled study showed that taking multiple anticonvulsant drugs results in dramatic changes in the way the body utilizes vitamin A.493 Further controlled research is needed to determine whether supplemental vitamin A might prevent birth defects in children born to women on multiple anticonvulsant therapy. Other research suggests that ingestion of large amounts of vitamin A may promote the development of birth defects, although the studies are conflicting.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Simvastatin

      A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found blood vitamin A levels increased over two years of therapy.494 Until more is known, people taking HMG-CoA reductase inhibitors, including simvastatin, should have blood levels of vitamin A monitored if they intend to supplement vitamin A.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Thioguanine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.495 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Thiotepa

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.496 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Uracil Mustard

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.497 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

    • Vinblastine

      Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.499 However, most scientific research does not support this supposition.

      A modified form of vitamin A has been reported to work synergistically with chemotherapy in test tube research.500 Vitamin C appears to increase the effectiveness of chemotherapy in animals501 and with human breast cancer cells in test tube research.502 In a double-blind study, Japanese researchers found that the combination of vitamin E , vitamin C, and N-acetyl cysteine (NAC) ?all antioxidants?protected against chemotherapy-induced heart damage without interfering with the action of the chemotherapy.503

      A comprehensive review of antioxidants and chemotherapy leaves open the question of whether supplemental antioxidants definitely help people with chemotherapy side effects, but neither does it show that antioxidants should be avoided for fear that the actions of chemotherapy are interfered with.504 Although research remains incomplete, the idea that people taking chemotherapy should avoid antioxidants is not supported by scientific research.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    • Vincristine

      A controlled French trial reported that when postmenopausal late-stage breast cancer patients were given very large amounts of vitamin A (350,000?500,000 IU per day) along with chemotherapy, remission rates were significantly better than when the chemotherapy was not accompanied by vitamin A.505 Similar results were not found in premenopausal women. The large amounts of vitamin A used in the study are toxic and require clinical supervision.

      The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
    The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers? package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

    Side Effects

    Side Effects

    Since a 1995 report from the New England Journal of Medicine, 506 women who are or could become pregnant have been told by doctors to take less than 10,000 IU (3,000 mcg) per day of vitamin A to avoid the risk of birth defect . A recent report studied several hundred women exposed to 10,000?300,000 IU (median exposure of 50,000 IU) per day.507 Three major malformations occurred in this study, but all could have happened in the absence of vitamin A supplementation. Surprisingly, no congenital malformations happened in any of the 120 infants exposed to maternal intakes of vitamin A that exceeded 50,000 IU per day. In fact, the high-exposure group had a 50% decreased risk for malformations compared with infants not exposed to vitamin A. The authors noted that some previous studies found no link between vitamin A and birth defects, and argued the studies that did find such a link suffered from various weaknesses. A closer look at the recent study reveals a 32% higher than expected risk of birth defects in infants exposed to 10,000?40,000 IU of vitamin A per day, but paradoxically a 37% decreased risk for those exposed to even higher levels. This suggests that both ?higher? and ?lower? risks may have been due to chance.

    Excessive dietary intake of vitamin A has been associated with birth defects in humans in fewer than 20 reported cases over the past 30 years.508 , 509 Presently, the level at which vitamin A supplementation may cause birth defects is not known, though combined human and animal data suggest that 30,000 IU per day should be considered safe.510 Women who are or who could become pregnant should consult with a doctor before supplementing with more than 10,000 IU per day.

    Vitamin A supplements can both help and hurt children. Many people have heard that vitamin A supplements support immune function and prevent infections . This is true under some circumstances. However, vitamin A can also increase the risk of infections, according to the findings of a double-blind trial.511 In a study of African children between six months and five years old, a 44% reduction in the risk of severe diarrhea was seen in those children given four 100,000?200,000 IU applications of vitamin A (the lower amount for those less than a year old) during an eight-month period. On further investigation, the researchers discovered that the reduction in diarrhea occurred only in children who were very malnourished. For children who were not starving, vitamin A supplementation actually increased the risk of diarrhea compared with the placebo group. The vitamin A-supplemented children also had a 67% increased risk of coughing and rapid breathing, signs of further lung infection, although this problem did not appear in children infected with AIDS. These findings should be of concern to American parents, whose children are not usually infected with AIDS or severely malnourished. Such relatively healthy children fared poorly in the African trial in terms of both the risk of diarrhea and the risk of continued lung problems. Vitamin A provided no benefit to the well-nourished kids. Therefore, it makes sense to not give vitamin A supplements to children unless there is a special reason to do so, such as the presence of a condition causing malabsorption (e.g., celiac disease ).

    In a study of people with retinitis pigmentosa (a degenerative condition of the eye), participants received 15,000 IU of vitamin A per day for 12 years with no signs of adverse effects or toxicity.512 For other adults, intake above 25,000 IU (7,500 mcg) per day can?in rare cases?cause headaches, dry skin, hair loss, fatigue, bone problems, and liver damage.513 At higher levels (for example 100,000 IU per day) these problems become more common.

    A controlled clinical trial showed that people who took 25,000 IU of vitamin A per day for a median of 3.8 years had an 11% increase in triglycerides , a 3% increase in total cholesterol and a 1% decrease in HDL cholesterol compared to those who did not take vitamin A.514 Although the significance of these findings is not clear, people at risk for cardiovascular disease should use caution when considering long-term vitamin A supplementation.

    One study found that increasing the intake of vitamin A in the diet was associated with bone loss and risk of hip fracture, possibly due to a vitamin A-induced stimulation of cells that break down bone.515 In this study, a vitamin A intake greater than 5,000 IU per day, when compared to a lower intake, was associated with a reduction in bone mineral density that approximately doubles the risk of hip fracture. Beta-carotene (which can be used by the body to make vitamin A) has not been linked to reduced bone mass. Until more is known, people concerned about osteoporosis may consider taking beta-carotene supplements rather than supplementing with vitamin A.

    Data from test tube, animal, and human studies show that excessive vitamin A intake can accelerate bone loss and inhibit formation of new bone, increasing the risk of osteoporosis.516 In humans, small studies have found these effects at about 85,000?125,000 IU per day. 517 , 518

    References

    1. Little DR. Ambulatory management of common forms of anemia. Am Fam Physician 1999;59:1598?604 [review].

    2. Hodges RE, Sauberlich HE, Canham JE, et al. Hematopoietic studies in vitamin A deficiency. Am J Clin Nutr 1978;31:876?85 [review].

    3. Bloem MW. Interdependence of vitamin A and iron: an important association for programmes of anaemia control. Proc Nutr Soc 1995;54:501?8 [review].

    4. Lane M, Alfrey CP. The anemia of human riboflavin deficiency. Blood 1965;25:432?42.

    5. Orehek AJ, Kollas CD. Refractory postpartum anemia due to vitamin B6 deficiency. Ann Intern Med 1997;126(10):834?5 [letter].

    6. Iwama H, Iwase O, Hayashi S, et al. Macrocytic anemia with anisocytosis due to alcohol abuse and vitamin B6 deficiency. Rinsho Ketsueki 1998;39:1127?30 [in Japanese].

    7. Hirschmann JV, Raugi GJ. Adult scurvy. J Am Acad Dermatol 1999;41:895?906 [review].

    8. Summerfield AL, Steinberg FU, Gonzalez JG. Morphologic findings in bone marrow precursor cells in zinc-induced copper deficiency anemia. Am J Clin Pathol 1992;97:665?8.

    9. Freycon F, Pouyau G. Rare nutritional deficiency anemia: deficiency of copper and vitamin E. Sem Hop 1983;59:488?93 [review] [in French].

    10. Borgna-Pignatti C, Marradi P, Pinelli L, et al. Thiamine-responsive anemia in DIDMOAD syndrome. J Pediatr 1989;114:405?10.

    11. Neufeld EJ, Mandel H, Raz T, et al. Localization of the gene for thiamine-responsive megaloblastic anemia syndrome, on the long arm of chromosome 1, by homozygosity mapping. Am J Hum Genet 1997;61:1335?41.

    12. Benn CS, Aaby P, Bale C, et al. Randomised trial of effect of vitamin A supplementation on antibody response to measles vaccine in Guinea-Bissau, west Africa. Lancet 1997;350:101?5.

    13. Semba RD. Vitamin A as ?anti-infective? therapy, 1920?1940. J Nutr 1999;129:783?91 [review].

    14. Molina EL, Patel JA. A to Z: vitamin A and zinc, the miracle duo. Indian J Pediatr 1996;63:427?31 [review].

    15. Malvy D. Micronutrients and tropical viral infections: one aspect of pathogenic complexity in tropical medicine. Med Trop (Mars) 1999;59:442?8 [review; in French].

    16. World Health Organization. Expanded programme on immunization: programme for the prevention of blindness nutrition. Joint WHO/UNICEF statement. Vitamin A for measles. Wkly Epidemiol Rec 1987;62:133?4.

    17. Coutsoudis A, Broughton M, Coovadia HM. Vitamin A supplementation reduces measles morbidity in young African children: a randomized, placebo-controlled, double-blind trial. Am J Clin Nutr 1991;54:890?5.

    18. Rosales FJ, Kjolhede C. A single 210-mumol oral dose of retinol does not enhance the immune response in children with measles. J Nutr 1994;124:1604?14.

    19. Rahmathullah L. Effect of receiving a weekly dose of vitamin A equivalent to the recommended dietary allowances among pre school children on mortality in south India. Indian J Pediatr 1991;58:837?47.

    20. Vijayaraghavan K, Rashmiah G, Suryaprakasam B, et al. Effect of massive dose of vitamin A on morbidity and mortality in Indian children. Lancet 1990;336:1342?53.

    21. Glasziou PP, Mackerras DE. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70 [review].

    22. Frieden TR, Sowell AL, Henning JK, et al. Vitamin A levels and severity of measles: New York City. Am J Dis Child 1992;146:182?6.

    23. Committee on Infectious Diseases, American Academy of Pediatrics. Vitamin A treatment of Measles. Pediatrics 1993;91:1014?5.

    24. Coutsoudis A, Coovadia HM, Broughton M, et al. Micronutrient utilisation during measles treated with vitamin A or placebo. Int J Vitam Nutr Res 1991;61:199?204.

    25. Campos FA, Flores H, Underwood BA. Effect of an infection on vitamin A status of children as measured by the relative dose response. Am J Clin Nutr 1987;46:91?4.

    26. Ozsoylu S, Cemeroglu AP, Gunay M. Vitamin A for varicella. J Pediatr 1994;125:1017?8 [letter].

    27. Turck D, Michaud L. Cystic fibrosis: nutritional consequences and management. Baillieres Clin Gastroenterol 1998;12:805?22 [review].

    28. Lindemans J, Neijens HJ, Kerrebijn KF, Abels J. Vitamin B12 absorption in cystic fibrosis. Acta Paediatr Scand 1984;73:537?40.

    29. Gueant JL, Vidailhet M, Pasquet C, et al. Effect of pancreatic extracts on the faecal excretion and on the serum concentration of cobalamin and cobalamin analogues in cystic fibrosis. Clin Chim Acta 1984;137:33?41.

    30. Semba RD. Vitamin A, immunity, and infection. Clin Infect Dis 1994;19:489?99 [review].

    31. Glasziou PP, Mackerras DEM. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70.

    32. Stephensen CB, Franchi LM, Hernandez H, et al. Adverse effects of high-dose vitamin A supplements in children hospitalized with pneumonia. Pediatrics 1998;101(5):E3 [abstract].

    33. Bresee JS, Fischer M, Dowell SF, et al. Vitamin A therapy for children with respiratory syncytial virus infection: a multicenter trial in the United States. Pediatr Infect Dis J 1996;15:777?82.

    34. Quinlan KP, Hayani KC. Vitamin A and respiratory syncytial virus infection. Serum levels and supplementation trial. Arch Pediatr Adolesc Med 1996;150:25?30.

    35. Kjolhede CL, Chew FJ, Gadomski AM, et al. Clinical trial of vitamin A as adjuvant treatment for lower respiratory tract infections. J Pediatr 1995;126:807?12.

    36. Pinnock CB, Douglas RM, Badcock NR. Vitamin A status in children who are prone to respiratory tract infections. Aust Paediatr J 1986;22:95?9.

    37. Murphy S, West KP Jr, Greenough WB 3d, et al. Impact of vitamin A supplementation on the incidence of infection in elderly nursing-home residents: a randomized controlled trial. Age Ageing 1992;21:435?9.

    38. Fawzi WW, Mbise R, Spiegelman D, et al. Vitamin A supplements and diarrheal and respiratory tract infections among children in Dar es Salaam, Tanzania. J Pediatr 2000;137:660?7.

    39. Ross AC. Vitamin A supplementation as therapy?are the benefits disease specific? Am J Clin Nutr 1998;68:8?9 [review].

    40. Fawzi WW, Mbise RL, Fataki MR, et al. Vitamin A supplementation and severity of pneumonia in children admitted to the hospital in Dar es Salaam, Tanzania. Am J Clin Nutr 1998;68:187?92.

    41. Stich HF, Rosin MP, Hornby AP, et al. Remission of oral leukoplakias and micronuclei in tobacco/betel quid chewers treated with beta-carotene and with beta-carotene plus vitamin A. Int J Cancer 1988;42:195?9.

    42. Garewal HS, Katz RV, Meyskens F, et al. ß-Carotene produces sustained remission in patients with oral leukoplakia. Arch Otolaryngol Head Neck Surg 1999;125:1305?10.

    43. Liede K, Hietanen J, Saxen L, et al. Long-term supplementation with alpha-tocopherol and beta-carotene and prevalence of oral mucosal lesions in smokers. Oral Dis 1998;4:78?83.

    44. Toma S, Benso S, Albanese E, et al. Treatment of oral leukoplakia with beta-carotene. Oncology 1992;49:77?81.

    45. Garewal HS, Meyskens FL Jr, Killen D, et al. Response of oral leukoplakia to beta-carotene. J Clin Oncol 1990;8:1715?20.

    46. Lippman SM, Batsakis JG, Toth BB, et al. Comparison of low-dose isotretinoin with beta carotene to prevent oral carcinogenesis. N Engl J Med 1993;328:15?20.

    47. Johnson J, Ringsdorf W, Cheraskin E. Relationship of vitamin A and oral leukoplakia. Arch Derm 1963;88:607?12.

    48. Stich HF, Mathews B, Sankaranarayanan R, Nair MK. Remission of precancerous lesions in the oral cavity of tobacco chewers and maintenance of the protective effect of ß-carotene or vitamin A. Am J Clin Nutr 1991;53:298S?304S.

    49. Stich HF, Rosin MP, Hornby AP, et al. Remission of oral leukoplakias and micronuclei in tobacco/betel quid chewers treated with beta-carotene and with beta-carotene plus vitamin A. Int J Cancer 1988;42:195?9.

    50. Rumore MM. Vitamin A as an immunomodulating agent. Clin Pharm 1993;12:506?14 [review].

    51. West CE. Vitamin A and measles. Nutr Rev 2000;58:S46?S54.

    52. Glasziou PP, Mackerras DE. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70.

    53. Markowitz LE, Nzilambi N, Driskell WJ, et al. Vitamin A levels and mortality among hospitalized measles patients, Kinshasa, Zaire. J Trop Pediatr 1989;35:109?12.

    54. Arrieta AC, Zaleska M, Stutman HR, Marks MI. Vitamin A levels in children with measles in Long Beach, California. J Pediatr 1992;121:75?8.

    55. Butler JC, Havens PL, Sowell AL, et al. Measles severity and serum retinol (vitamin A) concentration among children in the United States. Pediatrics 1993;91:1176?81.

    56. Frieden TR, Sowell AL, Henning KJ, et al. Vitamin A levels and severity of measles. New York City. Am J Dis Child 1992;146:182?6.

    57. Glasziou PP, Mackerras DE. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70.

    58. Fawzi WW, Chalmers TC, Herrera MG, Mosteller F. Vitamin A supplementation and child mortality. A meta-analysis. JAMA 1993;269:898?903.

    59. Barclay AJ, Foster A, Sommer A. Vitamin A supplements and mortality related to measles: a randomised clinical trial. BMJ 1987;294:294?6.

    60. Glasziou PP, Mackerras DE. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70.

    61. Hussey GD, Klein M. A randomized, controlled trial of vitamin A in children with severe measles. N Engl J Med 1990;323:160?4.

    62. Kawasaki Y, Hosoya M, Katayose M, Suzuki H. The efficacy of oral vitamin A supplementation for measles and respiratory syncytial virus (RSV) infection. Kansenshogaku Zasshi 1999;73:104?9 [in Japanese].

    63. Ellison JB. Intensive vitamin A therapy in measles. BMJ 1932;2:708?11.

    64. Russell RM, Smith VC, Multak R, et al. Dark-adaptation testing for diagnosis of subclinical vitamin-A deficiency and evaluation of therapy. Lancet 1973;2:1161?4.

    65. Singh RB, Niaz MA, Sharma JP, et al. Plasma levels of antioxidant vitamins and oxidative stress in patients with acute myocardial infarction. Acta Cardiol 1994;49:441?52.

    66. Levy Y, Bartha P, Ben-Amotz A, et al. Plasma antioxidants and lipid peroxidation in acute myocardial infarction and thrombolysis. J Am Coll Nutr 1998;17:337?41.

    67. Singh RB, Niaz MA, Rastogi SS, Tastogi S. Usefulness of antioxidant vitamins in suspected acute myocardial infarction (the Indian experiment of infarct survival-3). Am J Cardiol 1996;77:232?6.

    68. Kardinaal AFM, Kok FJ, Ringstad J, et al. Antioxidants in adipose tissue and risk of myocardial infarction: the EURAMIC study. Lancet 1993;342:1379?84.

    69. Tavani A, Negri E, D?Avanzo B, La Vecchia C. Beta-carotene intake and risk of nonfatal acute myocardial infarction in women. Eur J Epidemiol 1997;13:631?7.

    70. Rapola JM, Virtamo J, Ripatti S, et al. Randomised trial of alpha-tocopherol and beta-carotene supplements on incidence of major coronary events in men with previous myocardial infarction. Lancet 1997;349:1715?20.

    71. Virtamo J, Rapola JM, Ripatti S, et al. Effect of vitamin E and beta carotene on the incidence of primary nonfatal myocardial infarction and fatal coronary heart disease. Arch Intern Med 1998;158:668?75.

    72. Klipstein-Grobusch K, Geleijnse JM, den Breeijen JH, et al. Dietary antioxidants and risk of myocardial infarction in the elderly: the Rotterdam Study. Am J Clin Nutr 1999;69:261?6.

    73. Semba RD. Vitamin A, immunity, and infection. Clin Infect Dis 1994;19:489?99 [review].

    74. Glasziou PP, Mackerras DEM. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70.

    75. Stephensen CB, Franchi LM, Hernandez H, et al. Adverse effects of high-dose vitamin A supplements in children hospitalized with pneumonia. Pediatrics 1998;101(5):E3 [abstract].

    76. Bresee JS, Fischer M, Dowell SF, et al. Vitamin A therapy for children with respiratory syncytial virus infection: a multicenter trial in the United States. Pediatr Infect Dis J 1996;15:777?82.

    77. Quinlan KP, Hayani KC. Vitamin A and respiratory syncytial virus infection. Serum levels and supplementation trial. Arch Pediatr Adolesc Med 1996;150:25?30.

    78. Kjolhede CL, Chew FJ, Gadomski AM, et al. Clinical trial of vitamin A as adjuvant treatment for lower respiratory tract infections. J Pediatr 1995;126:807?12.

    79. Pinnock CB, Douglas RM, Badcock NR. Vitamin A status in children who are prone to respiratory tract infections. Aust Paediatr J 1986;22:95?9.

    80. Murphy S, West KP Jr, Greenough WB 3d, et al. Impact of vitamin A supplementation on the incidence of infection in elderly nursing-home residents: a randomized controlled trial. Age Ageing 1992;21:435?9.

    81. Fawzi WW, Mbise R, Spiegelman D, et al. Vitamin A supplements and diarrheal and respiratory tract infections among children in Dar es Salaam, Tanzania. J Pediatr 2000;137:660?7.

    82. Ross AC. Vitamin A supplementation as therapy--are the benefits disease specific? Am J Clin Nutr 1998;68:8?9 [review].

    83. Fawzi WW, Mbise RL, Fataki MR, et al. Vitamin A supplementation and severity of pneumonia in children admitted to the hospital in Dar es Salaam, Tanzania. Am J Clin Nutr 1998;68:187?92.

    84. American Academy of Pediatrics Committee on Infectious Diseases. Vitamin A treatment of measles. Pediatrics 1993,91:1014?5.

    85. Penn ND, Purkins L, Kelleher J, et al. The effect of dietary supplementation with vitamins A, C and E on cell-mediated immune function in elderly long-stay patients: a randomized controlled trial. Age Ageing 1991;20:169?74.

    86. de la Fuente M, Ferrandez MD, Burgos MS, et al. Immune function in aged women is improved by ingestion of vitamins C and E. Can J Physiol Pharmacol 1998;76:373?80.

    87. Mejia LA, Chew F. Hematological effect of supplementing anemic children with vitamin A alone and in combination with iron. Am J Clin Nutr 1988;48:595?600.

    88. Lithgow DM, Politzer WM. Vitamin A in the treatment of menorrhagia. S Afr Med J 1977;51:191?3.

    89. Patty I, Benedek S, Deak G, et al. Controlled trial of vitamin A therapy in gastric ulcer. Lancet 1982;2(8303):876 [letter].

    90. Patty I, Tarnok F, Simon L, et al. A comparative dynamic study of the effectiveness of gastric cytoprotection by vitamin A, De-Nol, sucralfate and ulcer healing by pirenzepine in patients with chronic gastric ulcer (a multiclinical and randomized study). Acta Physiol Hung 1984;64:379?84.

    91. Molina EL, Patel JA. A to Z: vitamin A and zinc, the miracle duo. Indian J Pediatr 1996;63:427?31 [review].

    92. Malvy D. Micronutrients and tropical viral infections: one aspect of pathogenic complexity in tropical medicine. Med Trop (Mars) 1999;59:442?8 [review; in French].

    93. World Health Organization. Expanded programme on immunization: programme for the prevention of blindness nutrition. Joint WHO/UNICEF statement. Vitamin A for measles. Wkly Epidemiol Rec 1987;62:133?4.

    94. Coutsoudis A, Broughton M, Coovadia HM. Vitamin A supplementation reduces measles morbidity in young African children: a randomized, placebo-controlled, double-blind trial. Am J Clin Nutr 1991;54:890?5.

    95. Rosales FJ, Kjolhede C. A single 210-mumol oral dose of retinol does not enhance the immune response in children with measles. J Nutr 1994;124:1604?14.

    96. Rahmathullah L. Effect of receiving a weekly dose of vitamin A equivalent to the recommended dietary allowances among pre school children on mortality in south India. Indian J Pediatr 1991;58:837?47.

    97. Vijayaraghavan K, Rashmiah G, Suryaprakasam B, et al. Effect of massive dose of vitamin A on morbidity and mortality in Indian children. Lancet 1990;336:1342?53.

    98. Glasziou PP, Mackerras DE. Vitamin A supplementation in infectious diseases: a meta-analysis. BMJ 1993;306:366?70 [review].

    99. Frieden TR, Sowell AL, Henning JK, et al. Vitamin A levels and severity of measles: New York City. Am J Dis Child 1992;146:182?6.

    100. Committee on Infectious Diseases, American Academy of Pediatrics. Vitamin A treatment of Measles. Pediatrics 1993;91:1014?5.

    101. Coutsoudis A, Coovadia HM, Broughton M, et al. Micronutrient utilisation during measles treated with vitamin A or placebo. Int J Vitam Nutr Res 1991;61:199?204.

    102. Campos FA, Flores H, Underwood BA. Effect of an infection on vitamin A status of children as measured by the relative dose response. Am J Clin Nutr 1987;46:91?4.

    103. Ozsoylu S, Cemeroglu AP, Gunay M. Vitamin A for varicella. J Pediatr 1994;125:1017?8 [letter].

    104. Hunt TK. Vitamin A and wound healing. J Am Acad Dermatol 1986;15:817?21 [review].

    105. Hunt TK. Vitamin A and wound healing. J Am Acad Dermatol 1986;15:817?21 [review].

    106. Hunt TK, Ehrlich HP, Garcia JA, et al. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?41.

    107. Romney SL, Palan PR, Duttagupta C, et al. Retinoids and the prevention of cervical dysplasias. Am J Obstet Gynecol 1981;141:890?4.

    108. Kligman AM, Mills OH Jr, Leyden JJ, et al. Oral vitamin A in acne vulgaris. Preliminary report. Int J Dermatol 1981;20:278?85.

    109. Morgan MY, Levine JA. Alcohol and nutrition. Proc Natl Acad Sci 1988;47:85?98.

    110. Chapman K, Prabhudesai M, Erdman JW. Vitamin A status of alcoholics upon admission and after two weeks of hospitalization. J Am Coll Nutr 1993;12:77?83.

    111. Leo MA, Lieber CS. Alcohol, vitamin A, and beta-carotene: adverse interactions, including hepatotoxicity and carcinogenicity. Am J Clin Nutr 1999;69:1071?85 [review].

    112. Chen M, Boyce W, Hsu JM. Effect of ascorbic acid on plasma alcohol clearance. J Am Coll Nutr 1990;9:185?9.

    113. Rankov BG. Vitamin A and carotene concentration in serum in persons with chronic conjunctivitis and pterygium. Int J Vitam Nutr Res 1976;46:454?7 [in German].

    114. Dvorak AM. Vitamin A in Crohn?s disease. Lancet 1980;i:1303?4.

    115. Skogh M, Sundquist T, Tagesson C. Vitamin A in Crohn?s disease. Lancet 1980; i:766 [letter].

    116. Dvorak AM. Vitamin A in Crohn?s Disease. Lancet 1980;i:1303?4 [letter].

    117. Wright JP, Mee AS, Parfitt A, et al. Vitamin A therapy inpatients with Crohn?s disease. Gastroenterology 1985;88:512?4.

    118. Fawzi WW, Mbise R, Spiegelman D, et al. Vitamin A supplements and diarrheal and respiratory tract infections among children in Dar es Salaam, Tanzania. J Pediatr 2000;137:660?7.

    119. Frommer DJ. The healing of gastric ulcers by zinc sulphate. Med J Aust 1975;22(21):793?6.

    120. Keyvani F, Yassai M, Kimiagar M. Vitamin A status and endemic goiter. Int J Vitam Nutr Res 1988;58:155?60.

    121. Mesaros-Kanjski E, Kontosic I, Kusic Z, et al. Endemic goitre and plasmatic levels of vitamins A and E in the school-children on the island of Krk, Croatia. Coll Antropol 1999;23:729?36.

    122. Mesaros-Kanjski E, Kontosic I, Kusic Z, et al. Endemic goitre and plasmatic levels of vitamins A and E in the school-children on the island of Krk, Croatia. Coll Antropol 1999;23:729?36.

    123. Mutaku JF, Many MC, Colin I, et al. Antigoitrogenic effect of combined supplementation with dl-alpha-tocopherol, ascorbic acid and beta-carotene and of dl-alpha-tocopherol alone in the rat. J Endocrinol 1998;156:551?61.

    124. Semba RD, Graham NMH, Caiaffa WT, et al. Increased mortality associated with vitamin A deficiency during human immunodeficiency virus type 1 infection. Arch Intern Med 1993;153:2149?54.

    125. Semba RD, Miotti PG, Chiphangwi JD, et al. Maternal vitamin A deficiency and mother-to-child transmission of HIV-1. Lancet 1994;343:1593?7.

    126. Coutsoudis A, Pillay K, Spooner E, et al. Randomized trial testing the effect of vitamin A supplementation on pregnancy outcomes and early mother-to-child HIV-1 transmission in Durban, South Africa. South African Vitamin A Study Group. AIDS 1999;13:1517?24.

    127. Kennedy CM, Coutsoudis A, Kuhn L, et al. Randomized controlled trial assessing the effect of vitamin A supplementation on maternal morbidity during pregnancy and postpartum among HIV-infected women. J Acquir Immune Defic Syndr 2000;24:37?44.

    128. Fawzi WW, Msamanga G, Hunter D, et al. Randomized trial of vitamin supplements in relation to vertical transmission of HIV-1 in Tanzania. J Acquir Immune Defic Syndr 2000;23:246?54.

    129. Coutsoudis A, Bobat RA, Coovadia HM, et al. The effects of vitamin A supplementation on the morbidity of children born to HIV-infected women. Am J Public Health 1995;85:1076?81.

    130. Hanekom WA, Yogev R, Heald LM, et al. Effect of vitamin A therapy on serologic responses and viral load changes after influenza vaccination in children infected with the human immunodeficiency virus. J Pediatr 2000;136:550?2.

    131. Humphrey JH, Quinn T, Fine D, et al. Short-term effects of large-dose vitamin A supplementation on viral load and immune response in HIV-infected women. J Acquir Immune Defic Syndr Hum Retrovirol 1999;20:44?51.

    132. Smolle J, Wawschinek O, Hayn H, Eber O. Vitamin A and carotene in thyroid disease. Acta Med Austriaca 1983;10:71?3 [in German].

    133. Aktuna D, Buchinger W, Langsteger W, et al. Beta-carotene, vitamin A and carrier proteins in thyroid diseases. Acta Med Austriaca 1993;20:17?20 [in German].

    134. Mazzotta MY. Nutrition and wound healing. J Am Podiatr Med Assoc 1994;84:456?62 [review].

    135. Swartz-Basile DA, Rubin DC, Levin MS. Vitamin A status modulates intestinal adaptation after partial small bowel resection. JPEN J Parenter Enteral Nutr 2000;24:81?8.

    136. Ehrlich H, Hunt TK. Effects of cortisone and vitamin A on wound healing. Ann Surg 1968;167:324?8.

    137. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    138. Ehrlich HP, Tarver H, Hunt TK. Effects of vitamin A and glucocorticoids upon inflammation and collagen synthesis. Ann Surg 1973;177:222?7.

    139. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    140. Hunt TK. Vitamin A and wound healing. J Am Acad Dermatol 1986;15:817?21.

    141. Block E. The use of vitamin A in premenstrual tension. Acta Obstet Gynecol Scand 1960;39:586?92.

    142. Argonz J, Abinzano C. Premenstrual tension treated with vitamin A. J Clin Endocrinol 1950;10:1579?89.

    143. Tangney CC, Phillips G, Bell RA, et al. Selected indices of micronutrient status in adult patients with sickle cell anemia (SCA). Am J Hematol 1989;32:161?6.

    144. Chiu D, Vichinsky E, Ho SL, et al. Vitamin C deficiency in patients with sickle cell anemia. Am J Pediatr Hematol Oncol 1990;12:262?7.

    145. Jain SK, Ross JD, Duett J, Herbst JJ. Low plasma prealbumin and carotenoid levels in sickle cell disease patients. Am J Med Sci 1990;229:13?5.

    146. Jain SK, Williams DM. Reduced levels of plasma ascorbic acid (vitamin C) in sickle cell disease patients: its possible role in the oxidant damage to sickle cells in vitro. Clin Chim Acta 1985;149:257?61.

    147. Natta C, Stacewicz-Sapuntzakis M, Bhagavan H, Bowen P. Low serum levels of carotenoids in sickle cell anemia. Eur J Haematol 1988;41:131?5.

    148. Essein, EU. Plasma levels of retinol, ascorbic acid and alpha-tocopherol in sickle cell anemia. Centr Afr J Med 1995;41:48?50.

    149. Ndombi IO, Kinoti SN. Serum vitamin E and the sickling status in children with sickle cell anemia. East Afr Med J 1990;67:720?5.

    150. Phillips G, Tangney CC. Relationship of plasma alpha tocopherol to index of clinical severity in individuals with sickle cell anemia. Am J Hematol 1992;41:227?31.

    151. Natta CL, Machlin LJ, Brin M. A decrease in irreversibly sickled erythrocytes in sickle cell anemia patients given vitamin E. Am J Clin Nutr 1980;33:968?71.

    152. Crary EJ, McCarty MF. Potential clinical applications for high-dose nutritional antioxidants. Med Hypotheses 1984;13:77?98.

    153. Crary EJ, McCarty MF. Potential clinical applications for high-dose nutritional antioxidants. Med Hypotheses 1984;13:77?98.

    154. Hussey GD, Klein M. A randomized, controlled trial of vitamin A in children with severe measles. N Engl J Med 1990;323:160?4.

    155. Fuchs J. Potentials and limitations of the natural antioxidants RRR-alpha-tocopherol, L-ascorbic acid and beta-carotene in cutaneous photoprotection. Free Radic Biol Med 1998;25:848?73.

    156. Werninghaus K, Meydani M, Bhawan J, et al. Evaluation of the photoprotective effect of oral vitamin E supplementation. Arch Dermatol 1994;130:1257?61.

    157. Fuchs J, Kern H. Modulation of UV-light-induced skin inflammation by D-alpha-tocopherol and L-ascorbic acid: a clinical study using solar simulated radiation. Free Radic Biol Med 1998;25:1006?12.

    158. Eberlein-Konig B, Placzek M, Przybilla B. Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). J Am Acad Dermatol 1998;38:45?8.

    159. McArdle F, Rhodes LE, Parslew RA, et al. Effects of oral vitamin E and beta-carotene supplementation on ultraviolet radiation-induced oxidative stress in human skin. Am J Clin Nutr 2004;80:1270?5.

    160. Garmyn M, Ribaya-Mercado JD, Russel RM, et al. Effect of beta-carotene supplementation on the human sunburn reaction. Exp Dermatol 1995;4:104?11.

    161. Wolf C, Steiner A, Honigsmann H, et al. Do oral carotenoids protect human skin against UV erythema, psoralen phototoxicity, and UV-induced DNA damage? J Invest Dermatol 1988;90:55?57.

    162. Mathews-Roth MM, Pathak MA, Parrish J, et al. A clinical trial of the effects of oral beta-carotene on the responses of human skin to solar radiation. J Invest Dermatol 1972;59:349?53.

    163. Gollnick HP, Hopfenmuller W, Hemmes C, et al. Systemic B-carotene plus topical sunscreen are an optimal protection against harmful effects of natural UV-sunlight. Eur J Dermatol 1996;6:200?5.

    164. Lee J, Jiang S, Levine N, Watson RR. Carotenoid supplementation reduces erythema in human skin after simulated solar radiation exposure. Proc Soc Exp Biol Med 2000;223:170?4.

    165. Heinrich U, Gartner C, Wiebusch M, et al. Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema. J Nutr 2003;133:98?101.

    166. Aust O, Stahl W, Sies H, et al. Supplementation with tomato-based products increases lycopene, phytofluene, and phytoene levels in human serum and protects against UV-light-induced erythema. Int J Vitam Nutr Res 2005;75:54?60.

    167. Cesarini JP, Michel L, Maurette JM, et al. Immediate effects of UV radiation on the skin: modification by an antioxidant complex containing carotenoids. Photodermatol Photoimmunol Photomed 2003;19:182?9.

    168. Greul AK, Grundmann JU, Heinrich F, et al. Photoprotection of UV-irradiated human skin: an antioxidative combination of vitamins E and C, carotenoids, selenium and proanthocyanidins. Skin Pharmacol Appl Skin Physiol 2002;15:307?15.

    169. La Ruche G, Cesarini JP. Protective effect of oral selenium plus copper associated with vitamin complex on sunburn cell formation in human skin. Photodermatol Photoimmunol Photomed 1991;8:232?5.

    170. Sies H, Stahl W. Nutritional protection against skin damage from sunlight. Annu Rev Nutr 2004;24:173?200 [review].

    171. Sies H, Stahl W. Carotenoids and UV protection. Photochem Photobiol Sci 2004;3:749-52 [review].

    172. Fuchs J. Potentials and limitations of the natural antioxidants RRR-alpha-tocopherol, L-ascorbic acid and beta-carotene in cutaneous photoprotection. Free Radic Biol Med 1998;25:848?73.

    173. Werninghaus K, Meydani M, Bhawan J, et al. Evaluation of the photoprotective effect of oral vitamin E supplementation. Arch Dermatol 1994;130:1257?61.

    174. Fuchs J, Kern H. Modulation of UV-light-induced skin inflammation by D-alpha-tocopherol and L-ascorbic acid: a clinical study using solar simulated radiation. Free Radic Biol Med 1998;25:1006?12.

    175. Eberlein-Konig B, Placzek M, Przybilla B. Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). J Am Acad Dermatol 1998;38:45?8.

    176. McArdle F, Rhodes LE, Parslew RA, et al. Effects of oral vitamin E and beta-carotene supplementation on ultraviolet radiation-induced oxidative stress in human skin. Am J Clin Nutr 2004;80:1270?5.

    177. Garmyn M, Ribaya-Mercado JD, Russel RM, et al. Effect of beta-carotene supplementation on the human sunburn reaction. Exp Dermatol 1995;4:104?11.

    178. Wolf C, Steiner A, Honigsmann H, et al. Do oral carotenoids protect human skin against UV erythema, psoralen phototoxicity, and UV-induced DNA damage? J Invest Dermatol 1988;90:55?57.

    179. Mathews-Roth MM, Pathak MA, Parrish J, et al. A clinical trial of the effects of oral beta-carotene on the responses of human skin to solar radiation. J Invest Dermatol 1972;59:349?53.

    180. Gollnick HP, Hopfenmuller W, Hemmes C, et al. Systemic B-carotene plus topical sunscreen are an optimal protection against harmful effects of natural UV-sunlight. Eur J Dermatol 1996;6:200?5.

    181. Lee J, Jiang S, Levine N, Watson RR. Carotenoid supplementation reduces erythema in human skin after simulated solar radiation exposure. Proc Soc Exp Biol Med 2000;223:170?4.

    182. Heinrich U, Gartner C, Wiebusch M, et al. Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema. J Nutr 2003;133:98?101.

    183. Aust O, Stahl W, Sies H, et al. Supplementation with tomato-based products increases lycopene, phytofluene, and phytoene levels in human serum and protects against UV-light-induced erythema. Int J Vitam Nutr Res 2005;75:54?60.

    184. Cesarini JP, Michel L, Maurette JM, et al. Immediate effects of UV radiation on the skin: modification by an antioxidant complex containing carotenoids. Photodermatol Photoimmunol Photomed 2003;19:182?9.

    185. Greul AK, Grundmann JU, Heinrich F, et al. Photoprotection of UV-irradiated human skin: an antioxidative combination of vitamins E and C, carotenoids, selenium and proanthocyanidins. Skin Pharmacol Appl Skin Physiol 2002;15:307?15.

    186. La Ruche G, Cesarini JP. Protective effect of oral selenium plus copper associated with vitamin complex on sunburn cell formation in human skin. Photodermatol Photoimmunol Photomed 1991;8:232?5.

    187. Sies H, Stahl W. Nutritional protection against skin damage from sunlight. Annu Rev Nutr 2004;24:173?200 [review].

    188. Sies H, Stahl W. Carotenoids and UV protection. Photochem Photobiol Sci 2004;3:749-52 [review].

    189. Tyson JE, Wright LL, Oh W, et al. Vitamin A supplementation for extremely-low-birth-weight infants. N Engl J Med 1999;340:1962?8.

    190. Smolle J, Wawschinek O, Hayn H, Eber O. Vitamin A and carotene in thyroid disease. Acta Med Austriaca 1983;10:71?3 [in German].

    191. Aktuna D, Buchinger W, Langsteger W, et al. Beta-carotene, vitamin A and carrier proteins in thyroid diseases. Acta Med Austriaca 1993;20:17?20 [in German].

    192. Polidori MC, Mecocci P, Stahl W, et al. Plasma levels of lipophilic antioxidants in very old patients with type 2 diabetes. Diabetes Metab Res Rev 2000;16:15?9.

    193. Mejia LA, Chew F. Hematological effect of supplementing anemic children with vitamin A alone and in combination with iron. Am J Clin Nutr 1988;48:595?600.

    194. Muñoz EC, Rosado JL, Lopez P, et al. Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers. Am J Clin Nutr 2000;71:789?94.

    195. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    196. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    197. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    198. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    199. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    200. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    201. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    202. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    203. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    204. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    205. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    206. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    207. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    208. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    209. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    210. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    211. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    212. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    213. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    214. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    215. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    216. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    217. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    218. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    219. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    220. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 221?2 [review].

    221. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i?l.

    222. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i?l.

    223. Watkins DW, Cassidy MM, Khalafi R, Vahouny GV. Calcium and zinc balances in rats chronically fed the bile salt-sequestrant cholestyramine (Questran). Fed Proc 1983;42:819.

    224. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    225. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    226. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    227. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    228. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    229. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    230. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 221?2 [review].

    231. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i?l.

    232. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i?l.

    233. Watkins DW, Cassidy MM, Khalafi R, Vahouny GV. Calcium and zinc balances in rats chronically fed the bile salt-sequestrant cholestyramine (Questran). Fed Proc 1983;42:819.

    234. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 224 [review].

    235. Threlkeld DS, ed. Cardiovascular Drugs, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1999, 171L.

    236. Threlkeld DS(ed). Cardiovascular Drugs, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1999, 171L.

    237. Watkins DW, Cassidy MM, Khalafi R, Vahouny GV. Calcium and zinc balances in rats chronically fed the bile salt-sequestrant cholestyramine (Questran). Fed Proc 1983;42:819.

    238. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    239. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    240. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    241. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    242. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    243. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    244. Hu Y-J, Chen Y, Zhang Y-Q, et al. The protective role of selenium on the toxicity of cisplatin-contained chemotherapy regimen in cancer patients. Biol Trace Elem Res 1997;56:331?41.

    245. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    246. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    247. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    248. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    249. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    250. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    251. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    252. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    253. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    254. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    255. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    256. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    257. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    258. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    259. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    260. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    261. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    262. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    263. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    264. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    265. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    266. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    267. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    268. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    269. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    270. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    271. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    272. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    273. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    274. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    275. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    276. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    277. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    278. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    279. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    280. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    281. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    282. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    283. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    284. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    285. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    286. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    287. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    288. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    289. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    290. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    291. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    292. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    293. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    294. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    295. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    296. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    297. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    298. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    299. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    300. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    301. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    302. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 176.

    303. Clark JH, Russell GJ, Fitzgerald JF, Nagamori KE. Serum beta-carotene, retinol, and alpha-tocopherol levels during mineral oil therapy for constipation. Am J Dis Child 1987;141:1210?2.

    304. Roe DA. Drug-Induced Nutritional Deficiencies, 2d ed. Westport, CT: Avi Publishing, 1985, 157?8 [review].

    305. Holt GA. Food & Drug Interactions. Chicago: Precept Press,1998, 183.

    306. Van Gaal LF, Broom JI, Enzi G, Toplak H. Efficacy and tolerability of orlistat in the treatment of obesity: a 6-month dose ranging study. Orlistat Dose-Ranging Study Group. Eur J Clin Pharmacol 1998;54:125?32.

    307. Melia AT, Koss-Twardy SG, Zhi J. The effect of orlistat, an inhibitor of dietary fat absorption, on the absorption of vitamins A and E in healthy volunteers. J Clin Pharmacol 1996;36:647?53.

    308. James WP, Aveell A, Broom J, Whitehead J. A one-year trial to assess the value of orlistat in the management of obesity. Int J Obes Relat Metab Disord 1997;21 Suppl 3:S24?30.

    309. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    310. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    311. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    312. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    313. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    314. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    315. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    316. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    317. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    318. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    319. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    320. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    321. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    322. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    323. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    324. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    325. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    326. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    327. Curtis JL. Effects of medication on plasma vitamin A concentrations. Clin Chem 1976;22:695.

    328. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    329. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    330. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    331. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    332. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    333. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    334. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    335. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    336. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    337. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    338. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    339. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    340. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    341. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    342. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    343. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    344. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    345. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    346. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    347. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    348. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    349. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout 2 years of cholesterol-lowering therapy. Metabolism 1995;44:398?403.

    350. Moskowitz Y, Leibowitz E, Ronen M, Aviel E. Pseudotumor cerebri induced by vitamin A combined with minocycline. Ann Ophthalmol 1993;25:306?8.

    351. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    352. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    353. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    354. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    355. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    356. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    357. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    358. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    359. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    360. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    361. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    362. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    363. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    364. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    365. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    366. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    367. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    368. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    369. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    370. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg1969;170:633?40.

    371. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    372. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    373. Israel L, Hajji O, Grefft-Alami A, et al. Agumentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    374. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    375. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    376. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    377. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    378. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    379. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    380. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    381. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    382. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    383. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    384. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    385. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    386. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    387. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    388. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    389. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    390. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    391. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    392. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    393. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    394. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    395. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    396. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    397. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    398. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    399. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    400. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    401. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    402. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    403. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    404. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    405. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    406. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    407. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    408. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    409. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    410. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    411. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    412. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    413. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    414. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    415. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    416. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    417. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    418. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    419. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    420. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    421. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    422. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    423. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    424. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    425. Sacks PG, Harris D, Chou TC. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    426. Taper HS, et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    427. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    428. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    429. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    430. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout 2 years of cholesterol-lowering therapy. Metabolism 1995;44:398?403.

    431. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    432. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    433. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    434. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    435. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    436. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    437. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    438. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    439. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    440. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    441. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    442. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    443. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    444. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    445. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    446. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    447. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    448. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    449. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    450. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    451. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    452. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    453. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    454. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    455. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout two years of cholesterol-lowering therapy. Metabolism 1995;44:398?403.

    456. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    457. Joshi UM, Virkar KD, Amatayakul K, et al. Impact of hormonal contraceptives vis-a-vis non-hormonal factors on the vitamin status of malnourished women in India and Thailand. World Health Organization: Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Oral Contraceptives. Hum Nutr Clin Nutr 1986;40:205?20.

    458. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    459. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    460. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    461. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    462. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    463. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    464. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    465. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    466. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    467. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    468. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    469. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    470. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    471. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    472. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197?8.

    473. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 210?1 [review].

    474. Wynn V. Vitamins and oral contraceptive use. Lancet 1975;1:561?4.

    475. Berg G, Kohlmeier L, Brenner H. Effect of oral contraceptive progestins on serum copper concentration. Eur J Clin Nutr 1998;52:711?5.

    476. Holt GA. Food & Drug Interaction. Chicago: Precept Press, 1998, 197.

    477. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    478. Sacks PG, Harris D, Chou TC. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    479. Taper HS, de Gerlache J, Lans M, Roberfroid M. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    480. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    481. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    482. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    483. Hu YJ, Chen Y, Zhang YQ, et al. The protective role of selenium on the toxicity of cisplatin-contained chemotherapy regimen in cancer patients. Biol Trace Elem Res 1997;56:331?41.

    484. De Maria D, Falchi AM, Venturino P. Adjuvant radiotherapy of the pelvis with or without reduced glutathione: a randomized trial in patients operated on for endometrial cancer. Tumori 1992;78:374?6.

    485. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    486. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout two years of cholesterol-lowering therapy. Metabolism 1995;44:398?403.

    487. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    488. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    489. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    490. Hunt TK, Ehrlich HP, Garcia JA, Dunphy JE. Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man. Ann Surg 1969;170:633?40.

    491. Shenai JP, Mellen BG, Chytil F. Vitamin A status and postnatal dexamethasone treatment in bronchopulmonary dysplasia. Pediatrics 2000;106:547?53.

    492. Georgieff MK, Radmer WJ, Sowell AL. The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations. J Pediatr Gastroenterol Nutr 1991;13:376?82.

    493. Nau H, Tzimas G, Mondry M, et al. Antiepileptic drugs alter endogenous retinoid concentrations: a possible mechanism of teratogensis of anticonvulsant therapy. Life Sci 1995;57:53?60.

    494. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout 2 years of cholesterol-lowering therapy. Metabolism 1995;44:398?403.

    495. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    496. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    497. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    498. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    499. Witenberg B, Kalir HH, Raviv Z, et al. Inhibition by ascorbic acid of apoptosis induced by oxidative stress in HL-60 myeloid leukemia cells. Biochem Pharmacol 1999;57:823?32.

    500. Sacks PG, Harris D, Chou T-C. Modulation of growth and proliferation in squamous cell carcinoma by retinoic acid: A rationale for combination therapy with chemotherapeutic agents. Int J Cancer 1995;61:409?15.

    501. Taper HS et al. Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment. Int J Cancer 1987;40:575?9.

    502. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Letters 1996:103?19.

    503. Wagdi P, Fluri M, Aeschbacher B, et al. Cardioprotection in patients undergoing chemo- and/or radiotherapy for neoplastic disease. Jpn Heart J 1996;37:353?9.

    504. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treatment Rev 1997;23:209?40 [review].

    505. Israel L, Hajji O, Grefft-Alami A, et al. Augmentation par la vitamine A des effets de la chimiotherapie dans les cancers du sein metastases apres la menopause. Ann Med Interne 1985;136:551?4.

    506. Rothman KJ, Moore LL, Singer MR, et al. Teratogenicity of high vitamin A intake. N Engl J Med 1995;333:1369?73.

    507. Mastroiacovo P, Mazzone T, Addis A, et al. High vitamin A intake in early pregnancy and major malformations: a multicenter prospective controlled study. Teratology 1999;59:7?11.

    508. Biesalski HK. Comparative assessment of the toxicology of vitamin A and retinoids in man. Toxicology 1989;57:117?61.

    509. Azais-Braesco V, Pascal G. Vitamin A in pregnancy: requirements and safety limits. Am J Clin Nutr 2000;71(5 Suppl):1325S?33S [review].

    510. Wiegand UW, Hartmann S, Hummler H. Safety of vitamin A: recent results. Int J Vitam Nutr Res 1998;68:411?6 [review].

    511. Fawzi WW, Mbise R, Spiegelman D, et al. Vitamin A supplements and diarrheal and respiratory tract infections among children in Dar es Salaam, Tanzania. J Pediatr 2000;137:660?7.

    512. Sibulesky L, Hayes KC, Pronczuk A, et al. Safety of <7500 RE (<25000 IU) vitamin A daily in adults with retinitis pigmentosa. Am J Clin Nutr 1999;69:656?63.

    513. Bendich A, Langseth L. Safety of vitamin A. Am J Clin Nutr 1989;49:358?71.

    514. Cartmel B, Moon TE, Levine N. Effects of long-term intake of retinol on selected clinical and laboratory indexes. Am J Clin Nutr 1999;69:937?43.

    515. Melhus H, Michaelsson K, Kindmark A, et al. Excessive dietary intake of vitamin A is associated with reduced bone mineral density and increased risk for hip fracture. Ann Int Med 1998;129:770?8.

    516. Binkley N, Krueger D. Hypervitaminosis A and bone. Nutr Rev 2000;58:138?44 [review].

    517. Frame B, Jackson CE, Reynolds WA, Umphrey JE. Hypercalcemia and skeletal effects in chronic hypervitaminosis A. Ann Intern Med 1974;80:44?8.

    518. Patel P, Hanning RM, Atkinson SA, et al. Intoxication from vitamin A in an asthmatic child. CMAJ 1988;139:755?6.

    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

    Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.