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Vitamin A


What is it?

Vitamin A is a vitamin. It can be found in many fruits, vegetables, eggs, whole milk, butter, fortified margarine, meat, and oily saltwater fish. It can also be made in a laboratory.

Vitamin A is used for treating vitamin A deficiency. It is also used to reduce complications of diseases such as malaria, HIV, measles, and diarrhea in children with vitamin A deficiency.

Women use vitamin A for heavy menstrual periods, premenstrual syndrome (PMS), vaginal infections, yeast infections, “lumpy breasts” (fibrocystic breast disease), and to prevent breast cancer. Some women with HIV use vitamin A to decrease the risk of transmitting HIV to the baby during pregnancy, childbirth, or breast-feeding.

Men use vitamin A to raise their sperm count.

Some people use vitamin A for improving vision and treating eye disorders including age-related macular degeneration (AMD), glaucoma, and cataracts.

Vitamin A is also used for skin conditions including acne, eczema, psoriasis, cold sores, wounds, burns, sunburn, keratosis follicularis (Darier’s disease), ichthyosis (noninflammatory skin scaling), lichen planus pigmentosus, and pityriasis rubra pilaris.

It is also used for gastrointestinal ulcers, Crohn’s disease, gum disease, diabetes, Hurler syndrome (mucopolysaccharidosis), sinus infections, hayfever, and urinary tract infections (UTIs).

Vitamin A is also used for shigellosis, diseases of the nervous system, nose infections, loss of sense of smell, asthma, persistent headaches, kidney stones, overactive thyroid, iron-poor blood (anemia), deafness, ringing in the ears, and precancerous mouth sores (leukoplakia).

Other uses include preventing and treating cancer, protecting the heart and cardiovascular system, slowing the aging process, and boosting the immune system.

Vitamin A is applied to the skin to improve wound healing, reduce wrinkles, and to protect the skin against UV radiation.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for VITAMIN A are as follows:

Effective for...

  • Vitamin A deficiency. Taking vitamin A by mouth is effective for preventing and treating symptoms of vitamin A deficiency. Vitamin A deficiency can occur in people with protein deficiency, diabetes, over-active thyroid, fever, liver disease, cystic fibrosis, or an inherited disorder called abetalipoproteinemia.

Possibly effective for...

  • Breast cancer. Premenopausal women with a family history of breast cancer who consume high levels of vitamin A in their diet seem to have reduced risk of developing breast cancer. It is not known if taking vitamin A supplements has the same benefit.
  • Cataracts. Research suggests that high intake of vitamin A in the diet is linked to a lower risk of developing cataracts.
  • Diarrhea related to HIV. Taking vitamin A along with conventional medicines seems to decrease the risk of death from diarrhea in HIV-positive children with vitamin A deficiency.
  • Malaria. Taking vitamin A by mouth seems to decrease malaria symptoms in children less than 3 years-old living in areas where malaria is common.
  • Measles. Taking vitamin A by mouth seems to reduce the risk of measles complications or death in children with measles and vitamin A deficiency.
  • Precancerous lesions in the mouth (oral leukoplakia). Research suggests that taking vitamin A can help treat precancerous lesions in the mouth.
  • Recovery from laser eye surgery (photoreactive keratectomy). Taking vitamin A by mouth along with vitamin E seems to improve healing after laser eye surgery.
  • Complications after pregnancy. Taking vitamin A seems to reduce the risk of diarrhea and fever after pregnancy in malnourished women.
  • Complications during pregnancy. Taking vitamin A by mouth seems to reduce the risk of death and night blindness during pregnancy in malnourished women.
  • Eye disease affecting the retina (retinitis pigmentosa). Research suggests that taking vitamin A can slow the progression of an eye disease that causes damage to the retina.

Possibly ineffective for...

  • Breathing problems that affect newborns (bronchopulmonary dysplasia). Research shows that injecting vitamin does not reduce the risk of breathing problems in low birth weight infants.
  • Gastrointestinal side effects of chemotherapy. Taking vitamin A by mouth does not prevent or reduce gastrointestinal side effects of chemotherapy in children.
  • Fetal and early infant death. Taking vitamin A supplements before, during, or after pregnancy does not seem to reduce the risk of fetal or early infant death when taken by malnourished women. However, giving vitamin A to some infants seems to lower the risk of infant death in areas where malnutrition or vitamin A deficiency is common.
  • A type of skin cancer called melanoma. Research shows that taking vitamin A by mouth does not increase disease-free survival in people with melanoma.
  • Miscarriage. Women who take vitamin A by mouth, alone or in combination with other vitamins before or during early pregnancy, do not have a lower risk of miscarriage or stillbirth.
  • Osteoarthritis. Taking a specific product containing selenium, vitamin A, vitamin C, and vitamin E (Selenium ACE) does not appear to improve osteoarthritis. Also, taking additional vitamin A does not reduce pain in people with spinal osteoarthritis who have adequate levels of vitamin A.
  • Tuberculosis. Low levels of vitamin A are common in people with tuberculosis. However, taking vitamin A does not appear to improve symptoms or decrease the risk of death in people with tuberculosis.

Likely ineffective for...

  • Head and neck cancer. Taking vitamin A by mouth does not reduce the risk of developing new tumors or improve survival in people with head and neck cancer.
  • HIV transmission. Taking vitamin A by mouth does not lower the risk of passing HIV to the fetus during pregnancy, to newborns during delivery, or to infants during breastfeeding. In fact, early research suggests that HIV-positive women who take vitamin A supplements during pregnancy might have an increased risk of passing HIV to their babies through breast milk.
  • Lower respiratory tract infections. Taking vitamin A by mouth does not prevent or reduce symptoms of lower respiratory tract infections in children. In fact, vitamin A is linked to a slight increase in the risk of respiratory tract infections in children.
  • Pneumonia. Taking vitamin A by mouth does not help treat or prevent pneumonia in children living in developing countries.

Insufficient evidence to rate effectiveness for...

  • Alcohol-related liver disease. Early research shows that taking vitamin A together with coenzyme Q10 and other vitamins and minerals does not improve survival in people with alcohol-related liver disease.
  • Anemia. Taking vitamin A may help increase levels of proteins that store iron. This may reduce the risk of anemia in children and pregnant women. However, in developing nations in which anemia is common, taking vitamin A (retinol) with iron and folate does not seem to improve anemia in pregnant women compared to taking only iron and folate.
  • Cervical cancer. Research suggests that increased vitamin A levels in the blood or higher vitamin A intakes are associated with a lower risk of cervical cancer. However, this only appears to be the case when both forms of vitamin A, retinol and carotenes, are considered. Intake of retinol alone is not linked with a reduced risk of cervical cancer.
  • Child development. Taking vitamin A does not appear to improve growth in children with normal nutrition. However, taking vitamin A might improve growth in children with vitamin A deficiency.
  • Cancer that starts in the bone marrow (chronic myelogenous leukemia). Early research shows that taking a specific vitamin A product (Aquasol, Armour Pharmaceuticals) together with busulfan therapy does not improve survival in people with chronic myelogenous leukemia. Taking vitamin A with busulfan therapy might also increase the risk of toxicity.
  • Rectal damage caused by radiation therapy. Early research suggests that taking vitamin A (retinol palmitate) can reduce rectal symptoms caused by pelvic radiotherapy.
  • Colorectal cancer. Taking vitamin A alone or in combination with beta-carotene does not seem to prevent colorectal cancer.
  • Esophageal cancer. Some population research suggests that higher intake of beta-carotene and vitamin A is linked to a reduced risk of esophageal cancer. However, other higher quality evidence suggests that taking vitamin A in combination with beta-carotene does not prevent esophageal cancer.
  • HIV. Taking vitamin A during pregnancy does not seem to reduce the risk of death for the mother or child. Also, vitamin A supplementation during pregnancy does not seem to prevent HIV progression in women with HIV and low levels of vitamin A. However, giving vitamin A to HIV-positive infants and children seems to reduce the risk of HIV-related death.
  • Lung cancer. Early research suggests that taking vitamin A by mouth might improve survival and reduce the development of new tumors in people with lung cancer. However, other research shows that vitamin A has no effect on lung cancer survival. Also, vitamin A seems to increase the risk of lung cancer in smokers and people exposed to asbestos.
  • Ovarian cancer. Population research suggests that taking vitamin A does not reduce the risk of developing ovarian cancer.
  • Overall mortality. Giving vitamin A to children aged 6 months to 5 years seems to decrease the risk of death, especially in those at risk for vitamin deficiency. However, taking vitamin A does not seem to reduce the risk of death in healthy adults.
  • Pancreatic cancer. Taking vitamin A in combination with beta-carotene does not seem to prevent pancreatic cancer.
  • Prostate cancer. Vitamin A intake from the diet does not seem to be linked with a reduced risk of prostate cancer.
  • Stomach cancer. Taking vitamin A alone or with beta-carotene does not seem to prevent stomach cancer.
  • Promoting good vision.
  • Age-related macular degeneration (AMD).
  • Glaucoma.
  • Preventing and speeding recovery from infections.
  • Improving immune function.
  • Wound healing.
  • Relieving hay fever symptoms.
  • Other conditions.
More evidence is needed to rate vitamin A for these uses.

How does it work?

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Vitamin A is required for the proper development and functioning of our eyes, skin, immune system, and many other parts of our bodies.

Are there safety concerns?

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Vitamin A is LIKELY SAFE for most people when taken by mouth or given as a shot into the muscle in amounts less than 10,000 units daily.

Vitamin A is POSSBILY UNSAFE when taken by mouth in high doses. Some scientific research suggests that higher doses might increase the risk of osteoporosis and hip fracture, particularly in older people. Adults who eat low-fat dairy products, which are fortified with vitamin A, and a lot of fruits and vegetables usually do not need vitamin A supplements or multivitamins that contain vitamin A.

Long-term use of large amounts of vitamin A might cause serious side effects including fatigue, irritability, mental changes, anorexia, stomach discomfort, nausea, vomiting, mild fever, excessive sweating, and many other side effects. In women who have passed menopause, taking too much vitamin A can increase the risk of osteoporosis and hip fracture.

There is growing concern that taking high doses of antioxidant supplements such as vitamin A might do more harm than good. Some research shows that taking high doses of vitamin A supplements might increase the chance of death from all causes and possibly other serious side effects.

Vitamin A is LIKELY SAFE for children when taken in the recommended amounts. The maximum amounts of vitamin A that are safe for children are based on age:
  • Less than 2000 units/day in children up to 3 years old.
  • Less than 3000 units/day in children ages 4 to 8 years old.
  • Less than 5700 units/day in children ages 9 to 13 years old.
  • Less than 9300 units/day in children ages 14 to 18 years old.
Vitamin A is POSSIBLY UNSAFE for children when taken by mouth in high doses. When amounts greater than those recommended are taken, side effects can include irritability, sleepiness, vomiting, diarrhea, loss of consciousness, headache, vision problems, peeling skin, increased risk of pneumonia and diarrhea, and other problems.

Special precautions & warnings:

Pregnancy and breast-feeding: Vitamin A is LIKELY SAFE for pregnant or breast-feeding women when taken in recommended amounts of less than 10,000 units per day. Larger amounts are POSSIBLY UNSAFE. Vitamin A can cause birth defects. It is especially important for pregnant women to monitor their intake of vitamin A from all sources during the first three months of pregnancy. Forms of vitamin A are found in several foods including animal products, primarily liver, some fortified breakfast cereals, and dietary supplements.

Excessive use of alcohol: Drinking alcohol may increase vitamin A’s potentially harmful effects on the liver.

Disorders in which the body does not absorb fat properly: People with conditions that affect fat absorption, such as celiac disease, short gut syndrome, jaundice, cystic fibrosis, pancreatic disease, and cirrhosis of the liver, are not able to absorb vitamin A properly. To improve vitamin A absorption, these people should use vitamin A preparations that are water-soluble.

A type of high cholesterol called "Type V hyperlipoproteinemia:" This condition might increase the chance of vitamin A poisoning. Do not take vitamin A if you have this condition.

Intestinal infections: Intestinal infections such as hookworm can reduce how much vitamin A the body absorbs.

Liver disease: Too much vitamin A might make liver disease worse. Do not take vitamin A if you have liver disease.

Malnutrition: In people with severe protein malnutrition, taking vitamin A might result in having too much vitamin A in the body.

Zinc deficiency: Zinc deficiency might cause symptoms of vitamin A deficiency to occur. Taking a combination of vitamin A and zinc supplements might be necessary to improve this condition.

Are there interactions with medications?

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Major

Do not take this combination.

Medications for skin conditions (Retinoids)
Some medications for skin conditions have vitamin A effects. Taking vitamin A pills and these medications for skin conditions could cause too much vitamin A effects and side effects.

Moderate

Be cautious with this combination.

Antibiotics (Tetracycline antibiotics)
Vitamin A can interact with some antibiotics. Taking very large amounts of vitamin A along with some antibiotics can increase the chance of a serious side effect called intracranial hypertension. However, taking normal doses of vitamin A along with tetracyclines does not seem to cause this problem. Do not take large amounts of vitamin A if you are taking antibiotics.

Some of these antibiotics include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).

Medications that can harm the liver (Hepatotoxic drugs)
Taking large amounts of vitamin A might harm the liver. Taking large amounts of vitamin A along with medications that might also harm the liver can increase the risk of liver damage. Do not take large amounts of vitamin A if you are taking a medication that can harm the liver.

Some medications that can harm the liver include acetaminophen (Tylenol and others), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.

Warfarin (Coumadin)
Warfarin (Coumadin) is used to slow blood clotting. Large amounts of vitamin A can also slow blood clotting. Taking vitamin A along with warfarin (Coumadin) can increase the chances of bruising and bleeding. Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.

Are there interactions with herbs and supplements?

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Iron
Red blood cells need iron to make hemoglobin, the chemical that carries oxygen through the body. Taking vitamin A seems to improve hemoglobin levels in people who have low levels of iron and vitamin A.

Are there interactions with foods?

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Fatty foods
Eating fatty foods helps the body absorb vitamin A.

What dose is used?

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Adequate Intake (AI) levels of vitamin A for infants have been established: birth to 6 months, 400 mcg/day (1300 units); 7 to 12 months, 500 mcg/day (1700 units).

Recommended Dietary Allowance (RDA) levels for children and adults have been established: children 1 to 3 years, 300 mcg/day (1000 units); 4 to 8 years, 400 mcg/day (1300 units); 9 to 13 years, 600 mcg/day (2000 units); men 14 years and older, 900 mcg/day (3000 units); women 14 years and older, 700 mcg/day (2300 units); pregnancy 14 to 18 years, 750 mcg/day (2500 units); 19 years and older, 770 mcg/day (2600 units); lactation 14 to 18 years, 1200 mcg/day (4000 units); 19 years and older, 1300 mcg/day (4300 units). Tolerable Upper Intake Levels (UL) for vitamin A have also been established. The UL is the highest level of intake that is likely to pose no risk of harmful effects. The ULs for vitamin A are for preformed vitamin A (retinol) and do not include provitamin A carotenoids: infants and children from birth to 3 years, 600 mcg/day (2000 units); children 4 to 8 years, 900 mcg/day (3000 units); 9 to 13 years, 1700 mcg/day (6000 units); 14 to 18 years (including pregnancy and lactation), 2800 mcg/day (9000 units); adults age 19 and older (including pregnancy and lactation), 3000 mcg/day (10,000 units).

Vitamin A dosage is most commonly expressed in units, but dosage in micrograms is sometimes used.

Eating 5 servings of fruits and vegetables per day provides about 50% to 65% of the adult RDA for vitamin A.

Other names

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3-Dehydroretinol, 3-Déhydrorétinol, Acétate de Rétinol, Antixerophthalmic Vitamin, Axerophtholum, Dehydroretinol, Déhydrorétinol, Fat-Soluble Vitamin, Oleovitamin A, Palmitate de Rétinol, Retinoids, Rétinoïdes, Retinol, Rétinol, Retinol Acetate, Retinol Palmitate, Retinyl Acetate, Rétinyl Acétate, Retinyl Palmitate, Rétinyl Palmitate, Vitamin A Acetate, Vitamin A Palmitate, Vitamin A1, Vitamin A2, Vitamina A, Vitamine A, Vitamine A1, Vitamine A2, Vitamine Liposoluble, Vitaminum A.

Methodology

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To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).

References

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To see all references for the Vitamin A page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/964.html.

  1. Kennedy, K. A., Stoll, B. J., Ehrenkranz, R. A., Oh, W., Wright, L. L., Stevenson, D. K., Lemons, J. A., Sowell, A., Mele, L., Tyson, J. E., and Verter, J. Vitamin A to prevent bronchopulmonary dysplasia in very-low-birth-weight infants: has the dose been too low? The NICHD Neonatal Research Network. Early Hum Dev. 7-24-1997;49:19-31. View abstract.
  2. Potential interventions for the prevention of childhood pneumonia in developing countries: a meta-analysis of data from field trials to assess the impact of vitamin A supplementation on pneumonia morbidity and mortality. The Vitamin A and Pneumonia Working Group. Bull World Health Organ 1995;73:609-619. View abstract.
  3. Shankar, A. V., West, K. P., Jr., Gittelsohn, J., Katz, J., and Pradhan, R. Chronic low intakes of vitamin A-rich foods in households with xerophthalmic children: a case-control study in Nepal. Am J Clin Nutr 1996;64:242-248. View abstract.
  4. Fawzi, W. W., Chalmers, T. C., Herrera, M. G., and Mosteller, F. Vitamin A supplementation and child mortality. A meta-analysis. JAMA 2-17-1993;269:898-903. View abstract.
  5. Gopaldas, T., Gujral, S., and Abbi, R. Prevalence of xerophthalmia and efficacy of vitamin A prophylaxis in preventing xerophthalmia co-existing with malnutrition in rural Indian children. J Trop.Pediatr 1993;39:205-208. View abstract.
  6. Meyskens, F. L., Jr., Liu, P. Y., Tuthill, R. J., Sondak, V. K., Fletcher, W. S., Jewell, W. R., Samlowski, W., Balcerzak, S. P., Rector, D. J., Noyes, R. D., and . Randomized trial of vitamin A versus observation as adjuvant therapy in high-risk primary malignant melanoma: a Southwest Oncology Group study. J Clin Oncol. 1994;12:2060-2065. View abstract.
  7. Meyskens, F. L., Jr., Kopecky, K. J., Appelbaum, F. R., Balcerzak, S. P., Samlowski, W., and Hynes, H. Effects of vitamin A on survival in patients with chronic myelogenous leukemia: a SWOG randomized trial. Leuk.Res 1995;19:605-612. View abstract.
  8. Stich, H. F., Hornby, A. P., Mathew, B., Sankaranarayanan, R., and Nair, M. K. Response of oral leukoplakias to the administration of vitamin A. Cancer Lett 1988;40:93-101. View abstract.
  9. Shenai, J. P., Kennedy, K. A., Chytil, F., and Stahlman, M. T. Clinical trial of vitamin A supplementation in infants susceptible to bronchopulmonary dysplasia. J Pediatr 1987;111:269-277. View abstract.
  10. Sinclair, D., Abba, K., Grobler, L., and Sudarsanam, T. D. Nutritional supplements for people being treated for active tuberculosis. Cochrane.Database.Syst.Rev. 2011;:CD006086. View abstract.
  1. Gogia, S. and Sachdev, H. S. Vitamin A supplementation for the prevention of morbidity and mortality in infants six months of age or less. Cochrane.Database.Syst.Rev. 2011;:CD007480. View abstract.
  2. Haider, B. A. and Bhutta, Z. A. Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in developing countries. Cochrane.Database.Syst.Rev. 2011;:CD006980. View abstract.
  3. Mayo-Wilson, E., Imdad, A., Herzer, K., Yakoob, M. Y., and Bhutta, Z. A. Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis. BMJ 2011;343:d5094. View abstract.
  4. Fritz, H., Kennedy, D., Fergusson, D., Fernandes, R., Doucette, S., Cooley, K., Seely, A., Sagar, S., Wong, R., and Seely, D. Vitamin A and retinoid derivatives for lung cancer: a systematic review and meta analysis. PLoS.One. 2011;6:e21107. View abstract.
  5. Humphreys, E. H., Smith, N. A., Azman, H., McLeod, D., and Rutherford, G. W. Prevention of diarrhoea in children with HIV infection or exposure to maternal HIV infection. Cochrane Database Syst Rev 2010;:CD008563. View abstract.
  6. Mathew, J. L. Vitamin A supplementation for prophylaxis or therapy in childhood pneumonia: a systematic review of randomized controlled trials. Indian Pediatr 2010;47:255-261. View abstract.
  7. Sudfeld, C. R., Navar, A. M., and Halsey, N. A. Effectiveness of measles vaccination and vitamin A treatment. Int J Epidemiol 2010;39 Suppl 1:i48-i55. View abstract.
  8. Gogia, S. and Sachdev, H. S. Neonatal vitamin A supplementation for prevention of mortality and morbidity in infancy: systematic review of randomised controlled trials. BMJ 2009;338:b919. View abstract.
  9. Kongnyuy, E. J., Wiysonge, C. S., and Shey, M. S. A systematic review of randomized controlled trials of prenatal and postnatal vitamin A supplementation of HIV-infected women. Int J Gynaecol Obstet 2009;104:5-8. View abstract.
  10. Chen, H., Zhuo, Q., Yuan, W., Wang, J., and Wu, T. Vitamin A for preventing acute lower respiratory tract infections in children up to seven years of age. Cochrane Database Syst Rev 2008;:CD006090. View abstract.
  11. Darlow, B. A. and Graham, P. J. Vitamin A supplementation to prevent mortality and short and long-term morbidity in very low birthweight infants. Cochrane Database Syst Rev 2007;:CD000501. View abstract.
  12. Huiming, Y., Chaomin, W., and Meng, M. Vitamin A for treating measles in children. Cochrane Database Syst Rev 2005;:CD001479. View abstract.
  13. Ni, J., Wei, J., and Wu, T. Vitamin A for non-measles pneumonia in children. Cochrane Database Syst Rev 2005;:CD003700. View abstract.
  14. Rumbold, A., Middleton, P., and Crowther, C. A. Vitamin supplementation for preventing miscarriage. Cochrane Database Syst Rev 2005;:CD004073. View abstract.
  15. Ehrenpreis, E. D., Jani, A., Levitsky, J., Ahn, J., and Hong, J. A prospective, randomized, double-blind, placebo-controlled trial of retinol palmitate (vitamin A) for symptomatic chronic radiation proctopathy. Dis.Colon Rectum 2005;48:1-8. View abstract.
  16. Pearson, E., Bose, C., Snidow, T., Ransom, L., Young, T., Bose, G., and Stiles, A. Trial of vitamin A supplementation in very low birth weight infants at risk for bronchopulmonary dysplasia. J Pediatr 1992;121:420-427. View abstract.
  17. Singh, V. and West, K. P., Jr. Vitamin A deficiency and xerophthalmia among school-aged children in Southeastern Asia. Eur J Clin Nutr 2004;58:1342-1349. View abstract.
  18. Mahmud, Z. and Ali, S. M. Role of vitamin A and E in spondylosis. Bangladesh Med Res Counc.Bull 1992;18:47-59. View abstract.
  19. Grotto, I., Mimouni, M., Gdalevich, M., and Mimouni, D. Vitamin A supplementation and childhood morbidity from diarrhea and respiratory infections: a meta-analysis. J Pediatr 2003;142:297-304. View abstract.
  20. Bhandari, N., Bahl, R., and Taneja, S. Effect of micronutrient supplementation on linear growth of children. Br.J Nutr. 2001;85 Suppl 2:S131-S137. View abstract.
  21. Darlow, B. A. and Graham, P. J. Vitamin A supplementation for preventing morbidity and mortality in very low birthweight infants. Cochrane Database Syst Rev 2000;:CD000501. View abstract.
  22. Hill, J. and Bird, H. A. Failure of selenium-ace to improve osteoarthritis. Br.J Rheumatol. 1990;29:211-213. View abstract.
  23. Stewart, S., Prince, M., Bassendine, M., Hudson, M., James, O., Jones, D., Record, C., and Day, C. P. A randomized trial of antioxidant therapy alone or with corticosteroids in acute alcoholic hepatitis. J Hepatol. 2007;47:277-283. View abstract.
  24. de Klerk, N. H., Musk, A. W., Ambrosini, G. L., Eccles, J. L., Hansen, J., Olsen, N., Watts, V. L., Lund, H. G., Pang, S. C., Beilby, J., and Hobbs, M. S. Vitamin A and cancer prevention II: comparison of the effects of retinol and beta-carotene. Int.J.Cancer 1-30-1998;75:362-367. View abstract.
  25. Sankaranarayanan, R., Mathew, B., Varghese, C., Sudhakaran, P. R., Menon, V., Jayadeep, A., Nair, M. K., Mathews, C., Mahalingam, T. R., Balaram, P., and Nair, P. P. Chemoprevention of oral leukoplakia with vitamin A and beta carotene: an assessment. Oral Oncol. 1997;33:231-236. View abstract.
  26. Thorne-Lyman, A. L. and Fawzi, W. W. Vitamin A and carotenoids during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis. Paediatr.Perinat.Epidemiol. 2012;26 Suppl 1:36-54. View abstract.
  27. Bjelakovic, G., Nikolova, D., Gluud, L. L., Simonetti, R. G., and Gluud, C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane.Database.Syst.Rev. 2012;3:CD007176. View abstract.
  28. Zhang, X., Dai, B., Zhang, B., and Wang, Z. Vitamin A and risk of cervical cancer: a meta-analysis. Gynecol.Oncol. 2012;124:366-373. View abstract.
  29. Fulan, H., Changxing, J., Baina, W. Y., Wencui, Z., Chunqing, L., Fan, W., Dandan, L., Dianjun, S., Tong, W., Da, P., and Yashuang, Z. Retinol, vitamins A, C, and E and breast cancer risk: a meta-analysis and meta-regression. Cancer Causes Control 2011;22:1383-1396. View abstract.
  30. van den Broek, N., Dou, L., Othman, M., Neilson, J. P., Gates, S., and Gulmezoglu, A. M. Vitamin A supplementation during pregnancy for maternal and newborn outcomes. Cochrane.Database.Syst.Rev. 2010;:CD008666. View abstract.
  31. Oliveira-Menegozzo, J. M., Bergamaschi, D. P., Middleton, P., and East, C. E. Vitamin A supplementation for postpartum women. Cochrane.Database.Syst.Rev. 2010;:CD005944. View abstract.
  32. Kubo, A. and Corley, D. A. Meta-analysis of antioxidant intake and the risk of esophageal and gastric cardia adenocarcinoma. Am.J.Gastroenterol. 2007;102:2323-2330. View abstract.
  33. Irlam, J. H., Visser, M. E., Rollins, N., and Siegfried, N. Micronutrient supplementation in children and adults with HIV infection. Cochrane.Database.Syst.Rev 2005;:CD003650. View abstract.
  34. Cho, E., Hunter, D. J., Spiegelman, D., Albanes, D., Beeson, W. L., van den Brandt, P. A., Colditz, G. A., Feskanich, D., Folsom, A. R., Fraser, G. E., Freudenheim, J. L., Giovannucci, E., Goldbohm, R. A., Graham, S., Miller, A. B., Rohan, T. E., Sellers, T. A., Virtamo, J., Willett, W. C., and Smith-Warner, S. A. Intakes of vitamins A, C and E and folate and multivitamins and lung cancer: a pooled analysis of 8 prospective studies. Int.J.Cancer 2-15-2006;118:970-978. View abstract.
  35. Ramakrishnan U., Nguyen P., Martorell R. Effects of micronutrients on growth of children under 5 y of age: meta-analyses of single and multiple nutrient interventions. Am J Clin Nutr 2009;89:191-203. View abstract.
  36. Smedts HP, de Vries JH, Rakhshandehroo M, et al. High maternal vitamin E intake by diet or supplements is associated with congenital heart defects in the offspring. BJOG 2009;116:416-23. View abstract.
  37. Bjelakovic G, Nikolova D, Gluud LL, et al. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. JAMA 2007;297:842-57. View abstract.
  38. Dagnelie PC, Schuurman AG, Goldbohm RA, Van den Brandt PA. Diet, anthropometric measures and prostate cancer risk: a review of prospective cohort and intervention studies. BJU Int 2004;93:1139-50. View abstract.
  39. Bjelakovic G, Nikolova D, Simonetti RG, Gluud C. Antioxidant supplements for prevention of gastrointestinal cancers: a systematic review and meta-analysis. Lancet 2004;364:1219-28. View abstract.
  40. Azais-Braesco V, Pascal G. Vitamin A in pregnancy: requirements and safety limits. Am J Clin Nutr 2000;71:1325S-33S. View abstract.
  41. Sjostrom L, Rissanen A, Andersen T, et al. Randomised placebo-controlled trial of orlistat for weight loss and prevention of weight regain in obese patients. Lancet 1998;352:167-73.. View abstract.
  42. Davidson MH, Hauptman J, DiGirolamo M, et al. Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat. JAMA 1999;281:235-42. View abstract.
  43. Lipid Research Clinics Program. The Lipid Research Clinics' Coronary Primary Prevention Trial Results: 1. Reduction in incidence of coronary heart disease. JAMA 1984;251:351-64. View abstract.
  44. Probstfield JL, Lin TL, Peters J, Hunninghake DB. Carotenoids and vitamin A: the effect of hypocholesterolemic agents on serum levels. Metabolism 1985;34:88-91. View abstract.
  45. Glueck CJ, Tsang RC, Fallat RW, Scheel D. Plasma vitamin A and E levels in children with familial type II hyperlipoproteinemia during therapy with diet and cholestyramine resin. Pediatrics 1974;54:51-5.. View abstract.
  46. Schade RWB, van't Laar A, Majoor CLH, Jansen AP. A comparative study of the effects of cholestyramine and neomycin in the treatment of type II hyperlipoproteinemia. Acta Med Scand 1976;199:175-80.. View abstract.
  47. Barrowman JA, Broomhall J, Cannon AM, et al. Impairment of vitamin A absorption by neomycin. Clin Sci 1972;42:17P. View abstract.
  48. Garrett-Laster M, Oaks L, Russell RM, Oaks E. A lowering effect of a pharmacological dose of vitamin E on serum vitamin A in normal adults. Nutr Res 1981;1:559-64.
  49. Jagadeesan V, Reddy V. Interrelationship between vitamin E and A: a clinical study. Clin Chim Acta 1978;90:71-4. View abstract.
  50. Ayres S, Mihan R, Scribner MD. Synergism of vitamins A and E with dermatologic applications. Cutis 1979;23:600-3, 689-90.. View abstract.
  51. Willett WC, Stampfer MJ, Underwood BA, et al. Vitamins A, E and carotene: effects of supplementation on their plasma levels. Am J Clin Nutr 1983;38:559-66.. View abstract.
  52. Bendich A, Langseth L. Safety of vitamin A. Am J Clin Nutr 1989;49:358-71.. View abstract.
  53. Kusin JA, Reddy V, Sivakumar B. Vitamin E supplements and the absorption of a massive dose of vitamin A. Am J Clin Nutr 1974;27:774-6. View abstract.
  54. Bauernfeind JC, Newmark H, Brin M. Vitamins A and E nutrition via intramuscular or oral route. Am J Clin Nutr 1974;27:234-53.. View abstract.
  55. DiPalma JR, Ritchie DM. Vitamin Toxicity. Annu Rev Pharmacol Toxicol 1977;17:133-48.. View abstract.
  56. Thorp VJ. Effect of oral contraceptive agents on vitamin and mineral requirements. J Am Diet Assoc 1980;76:581-4.. View abstract.
  57. Pearson MG, Littlewood SM, Bowden AN. Tetracycline and benign intracranial hypertension (letter). Br Med J 1981;282:568-9.. View abstract.
  58. Walters BN, Gubbay SS. Tetracycline and benign intracranial hypertension: report of five cases. Br Med J 1981;282:19-20.. View abstract.
  59. Hathcock JN, Hattan DG, Jenkins MY, et al. Evaluation of vitamin A toxicity. Am J Clin Nutr 1990;52:183-202.. View abstract.
  60. Ahmed F, Bamji MS, Iyengar L. Effect of oral contraceptive agents on vitamin nutrition status. Am J Clin Nutr 1975;28:606-15.. View abstract.
  61. Kokkonen J, Mottonen M, Karttunen TJ, Lanning M. Mucosal pathology of the upper gastrointestinal tract associated with intensive chemotherapy in children: vitamin A supplements do not prevent lesions. Pediatr Hematol Oncol 2002;19:181-92.. View abstract.
  62. Fawzi WW, Msamanga GI, Hunter D, et al. Randomized trial of vitamin supplements in relation to transmission of HIV-1 through breastfeeding and early child mortality. AIDS 2002;16:1935-44.. View abstract.
  63. French AL, Kirstein LM, Massad LS, et al. Association of vitamin A deficiency with cervical squamous intraepithelial lesions in human immunodeficiency virus-infected women. J Infect Dis 2000;182:1084-9.. View abstract.
  64. McDuffie JR, Calis KA, Booth SL, et al. Effects of orlistat on fat-soluble vitamins in obese adolescents. Pharmacotherapy 2002;22:814-22.. View abstract.
  65. Lynch SR. Interaction of iron with other nutrients. Nutr Rev 1997;55:102-10.. View abstract.
  66. Garcia-Casal MN, Layrisse M, Solano L, et al. Vitamin A and beta-carotene can improve nonheme iron absorption from rice, wheat and corn by humans. J Nutr 1998;128:646-50.. View abstract.
  67. Fishman SM, Christian P, West KP. The role of vitamins in the prevention and control of anaemia. Public Health Nutr 2000;3:125-50.. View abstract.
  68. Tyrer LB. Nutrition and the pill. J Reprod Med 1984;29:547-50.. View abstract.
  69. Mooij PN, Thomas CM, Doesburg WH, Eskes TK. Multivitamin supplementation in oral contraceptive users. Contraception 1991;44:277-88. View abstract.
  70. Meyskens FL Jr, Graham V, Chvapil M, et al. A phase I trial of beta-all-trans-retinoic acid delivered via a collagen sponge and a cervical cap for mild or moderate intraepithelial cervical neoplasia. J Natl Cancer Inst 1983;71:921-5.. View abstract.
  71. Ross AC. Addressing research questions with national survey data-the relation of vitamin A status to infection and inflammation. Am J Clin Nutr 2000;72:1069-70. View abstract.
  72. Ballew C, Bowman BA, Russell RM, et al. Serum retinyl esters are not associated with biochemical markers of liver dysfunction in adult participants in the third National Health and Nutrition Examination Survey (NHANES III), 1988--1994. Am J Clin Nutr 2001;73:934-40.. View abstract.
  73. Schunemann HJ, Grant BJ, Freudenheim JL, et al. The relation of serum levels of antioxidant vitamins C and E, retinol and carotenoids with pulmonary function in the general population. Am J Respir Crit Care Med 2001;163:1246-55.. View abstract.
  74. Botterweck AA, van den Brandt PA, Goldbohm RA. Vitamins, carotenoids, dietary fiber, and the risk of gastric carcinoma: results from a prospective study after 6.3 years of follow-up. Cancer 2000;88:737-48.. View abstract.
  75. Fairfield KM, Hankinson SE, Rosner BA, et al. Risk of ovarian carcinoma and consumption of vitamins A, C, and E and specific carotenoids: a prospective analysis. Cancer 2001;92:2318-26.. View abstract.
  76. Johansson S, Lind PM, Hakansson H, et al. Subclinical hypervitaminosis A causes fragile bones in rats. Bone 2002;31:685-9.. View abstract.
  77. Lips P. Hypervitaminosis A and fractures. N Engl J Med 2003;348:347-9. View abstract.
  78. Michaelsson K, Lithell H, Vessby B, Melhus H. Serum retinol levels and the risk of fracture. N Engl J Med 2003;348:287-94.. View abstract.
  79. Denke MA. Dietary retinol--a double-edged sword. JAMA 2002;287:102-4. View abstract.
  80. Semba RD, Kumwenda N, Taha TE, et al. Impact of vitamin A supplementation on anaemia and plasma erythropoietin concentrations in pregnant women: a controlled clinical trial. Eur J Haematol 2001;66:389-95.. View abstract.
  81. Zimmerman CL, Han S, Wiedmann TS. The absorption of retinoic acids from the gastrointestinal tract is dependent upon chemical structure. Cancer Chemother Pharmacol 2001;47:27-33.. View abstract.
  82. Harrison EH, Hussain MM. Mechanisms involved in the intestinal digestion and absorption of dietary vitamin A. J Nutr 2001;131:1405-8.. View abstract.
  83. Rahman MM, Wahed MA, Fuchs GJ, et al. Synergistic effect of zinc and vitamin A on the biochemical indexes of vitamin A nutrition in children. Am J Clin Nutr 2002;75:92-8. View abstract.
  84. Christian P, Khatry SK, Yamini S, et al. Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women. Am J Clin Nutr 2001;73:1045-51. View abstract.
  85. Kumar B, Cole WC, Prasad KN. Alpha tocopheryl succinate, retinoic acid and polar carotenoids enhanced the growth-inhibitory effect of a cholesterol-lowering drug on immortalized and transformed nerve cells in culture. J Am Coll Nutr 2001;20:628-36. View abstract.
  86. Prakash P, Russell RM, Krinsky NI. In vitro inhibition of proliferation of estrogen-dependent and estrogen-independent human breast cancer cells treated with carotenoids or retinoids. J Nutr 2001;131:1574-80. View abstract.
  87. Hickenbottom SJ, Follett JR, Lin Y, et al. Variability in conversion of beta-carotene to vitamin A in men as measured by using a double-tracer study design. Am J Clin Nutr 2002;75:900-7. View abstract.
  88. Pastorino U, Infante M, Maioli M, et al. Adjuvant treatment of stage I lung cancer with high-dose vitamin A. J Clin Oncol 1993;11:1216-22. View abstract.
  89. 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 Intern Med 1998;129:770-8. View abstract.
  90. Feskanich D, Singh V, Willett WC, Colditz GA. Vitamin A intake and hip fractures among postmenopausal women. JAMA 2002;287:47-54. View abstract.
  91. Leo MA, Lieber CS. Alcohol, vitamin A, and beta-carotene: adverse interactions, including hepatotoxicity and carcinogenicity. Am J Clin Nutr 1999;69:1071-85. View abstract.
  92. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002. Available at: www.nap.edu/books/0309072794/html/.
  93. Widschwendter M, Berger J, Hermann M, et al. Methylation and silencing of the retinoic acid receptor-beta2 gene in breast cancer. J Natl Cancer Inst 2000;92:826-32. View abstract.
  94. Sporn MB. Retinoids and demethylating agents-looking for partners. J Natl Cancer Inst 2000;92:780-1. View abstract.
  95. Cumming RG, Mitchell P, Smith W. Diet and cataract: the Blue Mountains Eye Study. Ophthalmology 2000;10:450-6. View abstract.
  96. Russell RM. The vitamin A spectrum: from deficiency to toxicity. Am J Clin Nutr 2000;71:878-84. View abstract.
  97. 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. View abstract.
  98. Christian P, West KP Jr, Khatry SK, et al. Vitamin A or beta-carotene supplementation reduces but does not eliminate maternal night blindness in Nepal. J Nutr 1998;128:1458-63. View abstract.
  99. West KP Jr, Katz J, Khatry SK, et al. Double-blind cluster, randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal. The NNIPS-2 Study Group. BMJ 1999;318:570-5. View abstract.
  100. Katz J, West KP Jr, Khatry SK, et al. Maternal low-dose vitamin A or {beta}-carotene supplementation has no effect on fetal loss and early infant mortality: a randomized, cluster trial in Nepal. Am J Clin Nutr 2000;71:1570-6. View abstract.
  101. Clark JH, Russell GJ, Fitzgerald JF, et al. Serum beta-carotene, retinol, and alpha-tocopherol levels during mineral oil therapy for constipation. Am J Dis Child 1987;141:1210-2. View abstract.
  102. Becker GL. The case against mineral oil. Am J Digestive Dis 1952;19:344-8. View abstract.
  103. Tonstad S, Silverstein M, Aksnes L, Ose L. Low dose colestipol in adolescents with familial hypercholesterolemia. Arch Dis Child 1996;74:157-60. View abstract.
  104. Schwarz KB, Goldstein PD, Witztum JL, et al. Fat-soluble vitamin concentrations in hypercholestrolemic children treated with colestipol. Pediatrics 1980;65:243-50. View abstract.
  105. Elinder LS, Hadell K, Johansson J, et al. Probucol treatment decreases serum concentrations of diet-derived antioxidants. Arterioscler Thromb Vasc Biol 1995;15:1057-63. View abstract.
  106. West RJ, Lloyd JK. The effect of cholestyramine on intestinal absorption. Gut 1975;16:93-8. View abstract.
  107. Hathcock JN. Metabolic mechanisms of drug-nutrient interactions. Fed Proc 1985;44:124-9. View abstract.
  108. FDA Talk Paper. Vitamin A and birth defects (T95-56). Food and Drug Administration, U.S. Department of Health and Human Services, Rockville, MD. October 6, 1995.
  109. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  110. Omenn GS, Goodman GE, Thornquist MD, et al. Effects of a combination of beta-carotene and vitamin A on lung cancer and cardiovascular disease. N Engl J Med 1996;334:1150-5. View abstract.
  111. Christian P, West KP, Khatry SK, et al. Vitamin A or beta-carotene supplementation reduces symptoms of illness in pregnant and lactating Nepali women. J Nutr 2000;130:2675-82. View abstract.
  112. Roche, Inc. Xenical package insert. Nutley, NJ. May 1999.
  113. 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. View abstract.
  114. van Zandwijk N, Dalesio O, Pastorino U, et al. EUROSCAN, a randomized trial of vitamin A and N-acetylcysteine in patients with head and neck cancer or lung cancer. For the European Organization for Research and Treatment of Cancer Head and Neck and Lung Cancer Cooperative Groups. J Natl Cancer Inst 2000;92:977-86. View abstract.
  115. Liu C, Russell RM, Seitz HK, et al. Ethanol enhances retinoic acid metabolism into polar metabolites in rat liver via induction of cytochrome P4502E1. Gastroenterology 2001;120:179-89. View abstract.
  116. Meyers DG, Maloley PA, Weeks D. Safety of antioxidant vitamins. Arch Intern Med 1996;156:925-35. View abstract.
  117. Wang Z, Boudjelal M, Kang S, et al. Ultraviolet irradiation of human skin causes functional vitamin A deficiency, preventable by all-trans retinoic acid pre-treatment. Nat Med 1999;5:418-22. View abstract.
  118. Kowalski TE, Falestiny M, Furth E, Malet PF. Vitamin A hepatotoxicity: a cautionary note regarding 25,000 IU supplements. Am J Med 1994;97:523-8. View abstract.
  119. 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. View abstract.
  120. Fawzi WW, Mbise RL, Hertzmark E, et al. A randomized trial of vitamin A supplements in relation to mortality among human immunodeficiency virus-infected and uninfected children in Tanzania. Pediatr Infect Dis J 1999;18:127-33. View abstract.
  121. Shankar AH, Genton B, Semba RD, et al. Effect of vitamin A supplementation on morbidity due to Plasmodium falciparum in young children in Papua New Guinea: a randomised trial. Lancet 1999;354:203-9. View abstract.
  122. Zhang S, Hunter DJ, Forman MR, et al. Dietary carotenoids and vitamins A, C, and E and risk of breast cancer. J Natl Cancer Inst 1999;91:547-56. View abstract.
  123. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  124. Vetrugno M, Maino A, Cardia G, et al. A randomised, double masked, clinical trial of high dose vitamin A and vitamin E supplementation after photorefractive keratectomy. Br J Ophthalmol 2001;85:537-9. View abstract.
  125. Wicke C, Halliday B, Allen D, et al. Effects of steroids and retinoids on wound healing. Arch Surg 2000;135:1265-70. View abstract.
  126. Griffiths JK. The vitamin A paradox. J Pediatr 2000;137:604-7.. View abstract.
  127. Berson EL, Rosner B, Sandberg MA, et al. A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa. Arch Ophthalmol 1993;111:761-72. View abstract.
  128. McKevoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
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