Vitamin A
Vitamin A is a fat-soluble vitamin with four major functions in the body: (1) It helps cells reproduce normally—a process called differentiation (cells that have not properly differentiated are more likely to undergo pre-cancerous changes). (2) It is required for vision; vitamin A maintains healthy cells in various structures of the eye and is required for the transduction of light into nerve signals in the retina. (3) It is required for normal growth and development of the embryo and fetus, influencing genes that determine the sequential development of organs in embryonic development. (4) It may be required for normal reproductive function, with influences on the function and development of sperm, ovaries and placenta.
- Reliable and relatively consistent scientific data showing a substantial health benefit.
- Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
- This interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
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.
This supplement has been used in connection with the following health conditions:
| Used for | Amount | Why |
|---|---|---|
Anemia and Vitamin A Deficiency | 10,000 to 25,000 IU daily |  [3 stars] Vitamin A deficiency can contribute to anemia, supplementing with this vitamin may restore levels and improve symptoms. |
Childhood Diseases | High doses of vitamin A may be used to treat measles or chicken pox, but only under a doctor's supervision | [3 stars] 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. |
Cystic Fibrosis | 5,000 to 10,000 IU daily | [3 stars] 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. |
Infection | See a doctor for evaluation of possible deficiency | [3 stars] Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms. |
Leukoplakia | 28,500 IU daily under medical supervision | [3 stars] Vitamin A has been shown to be effective against leukoplakia. |
Measles and Vitamin A Deficiency | 200,000 IU daily for two days under medical supervision | [3 stars] In developing countries where vitamin A deficiency is common, preventive supplementation with vitamin A reduced the risk of death in children with measles. |
Night Blindness | If deficient: 10,000 to 25,000 IU daily | [3 stars] Night blindness may be an early sign of vitamin A deficiency. Doctors often recommend supplementing with vitamin A per day to correct a deficiency. |
Celiac Disease and Vitamin A Deficiency | Consult a qualified healthcare practitioner |  [2 stars] Vitamin A deficiency may occur as a result of celiac disease, in which case vitamin A supplements or injections can be beneficial. |
Heart Attack | 50,000 IU daily | [2 stars] Taking vitamin A may reduce heart attack risk and may improve the outcome for people who have already had a heart attack. |
Immune Function | Consult a qualified healthcare practitioner | [2 stars] Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms. |
Menorrhagia | 50,000 IU of vitamin A each day taken under the supervision of a doctor | [2 stars] In one study, women with menorrhagia who took vitamin A showed significant improvement or complete normalization of menstrual blood loss. |
Peptic Ulcer | Take under medical supervision: 150,000 IU per day | [2 stars] 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. |
Severe Measles | Consult a qualified healthcare practitioner | [2 stars] Two studies of children with severe measles showed that supplementing with high doses vitamin A speeded recovery and reduced complications and pneumonia-related deaths. |
Wound Healing | Take under medical supervision: 25,000 IU daily | [2 stars] Vitamin A plays a central role in wound healing and may be useful as a supplement or in a topical ointment. |
Abnormal Pap Smear | Refer to label instructions |  [1 star] 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. |
Acne Vulgaris | Refer to label instructions | [1 star] 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. |
Alcohol Withdrawal | Refer to label instructions | [1 star] Because of potential liver damage, correcting the vitamin A deficiency common to alcoholics requires a doctor’s supervision to monitor liver function. |
Conjunctivitis and Blepharitis | Refer to label instructions | [1 star] Vitamin A deficiency has been reported in people with chronic conjunctivitis, but it is unknown whether vitamin A supplementation can help the condition. |
Crohn’s Disease | Refer to label instructions | [1 star] 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. |
Diarrhea | Refer to label instructions | [1 star] 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. |
Gastritis | Refer to label instructions | [1 star] Vitamin A appears to reduce ulcer size and pain in people with ulcers and may help treat gastritis. |
Goiter | Refer to label instructions | [1 star] 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. |
HIV and AIDS Support | Refer to label instructions | [1 star] 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. |
Hypothyroidism | Refer to label instructions | [1 star] 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. |
Pre- and Post-Surgery Health | Refer to label instructions | [1 star] Topical vitamin A may help speed wound healing and reduce scarring in patients taking corticosteroids, which typically slow wound healing. |
Premenstrual Syndrome | Refer to label instructions | [1 star] Very high amounts of vitamin A have reduced PMS symptoms in some studies. |
Sickle Cell Anemia | Refer to label instructions | [1 star] 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. |
Type 1 Diabetes (Selenium, Vitamin C, Vitamin E) | Refer to label instructions | [1 star] A combination of the antioxidants selenium, vitamin A, vitamin C, and vitamin E has been shown to improve diabetic retinopathy. |
Type 1 Diabetes and Diabetic Retinopathy (Selenium, Vitamin C, Vitamin E) | Refer to label instructions | [1 star] Antioxidant nutrients including selenium, vitamin A, vitamin C, and vitamin E may combat free radicals associated with diabetic retinopathy. |
Type 2 Diabetes and Diabetic Neuropathy (Selenium, Vitamin C, Vitamin E) | Refer to label instructions | [1 star] A combination of the antioxidants selenium, vitamin A, vitamin C, and vitamin E has been shown to improve diabetic retinopathy. |
Urinary Tract Infection | Refer to label instructions | [1 star] Vitamin A deficiency increases the risk of many infection, supplementing with it may restore levels and help support the immune system. |
Vaginitis | Refer to label instructions | [1 star] 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. |
Sunburn (Vitamin D) | Refer to label instructions | |
Sunburn (Vitamin E) | Refer to label instructions |
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The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2013.