Updated: March 2, 2019
Vitamin A is a vitamin that is also known as 3-Dehydroretinol, 3-Dehydroretinol, Acetate de Retinol, Antixerophthalmic Vitamin, Axerophtholum, or Dehydroretinol.
It can be found in many fruits, vegetables, eggs, whole milk, butter, fortified margarine, meat, and oily saltwater fish. There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products. The second type, provitamin A, is found in fruits, vegetables, and other plant-based products. The most common type of provitamin A in foods and dietary supplements is beta-carotene. However, it can also be made in a laboratory. Carotenoids are a group of yellow or orange chemicals found in plants, some of these can be converted to vitamin A in the body.
Vitamin A is a fat-soluble vitamin that is naturally present in many foods. Vitamin A is important for normal vision, the immune system, and reproduction. Vitamin A can be taken orally or as a shot into the muscle for treating vitamin A deficiency. It can reduce complications of diseases such as malaria, HIV, measles, and diarrhea, and also beneficial in improving growth in children with vitamin A deficiency. Vitamin A is required for the proper development and functioning of our eyes, skin, immune system, heart, lungs, kidneys and various parts of our bodies.
Vitamin A deficiency. Taking vitamin A orally 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.
Premenopausal women with a family history of breast cancer should consume high levels of vitamin A in their diet lower risk of breast cancer. Taking vitamin A supplements may have the same benefit.
Consume high amounts of vitamin A in your diet to lower the risk of developing cataracts.
Taking vitamin A orally can reduce the risk of measles complications or death in children with measles and vitamin A deficiency.
Taking vitamin A can help treat precancerous lesions in the mouth.
Taking vitamin A, during, and after pregnancy reduces diarrhea after giving birth in malnourished women.
Taking vitamin A before and during pregnancy seems to reduce the risk of death in malnourished women.
Taking vitamin A during pregnancy seems to reduce night blindness in malnourished women. Vitamin A might work better for this condition when taken with zinc.
Taking vitamin A can slow the progression of an eye disease that causes damage to the retina.
Injecting vitamin in low birth weight infants may not reduce the risk of breathing problems.
Taking vitamin A orally does not prevent or reduce gastrointestinal side effects of chemotherapy in children.
Taking vitamin A supplements before, during, or after pregnancy may not 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.
Taking vitamin A orally may not increase disease-free survival in people with melanoma which is a type of skin cancer.
Women who take vitamin A orally alone or in combination with other vitamins before or during early pregnancy, may not have a lower risk of miscarriage or stillbirth.
Taking a specific product containing selenium, vitamin A, vitamin C, and vitamin E (Selenium ACE) may improve osteoarthritis. However, taking additional vitamin A does not reduce pain in people with spinal osteoarthritis who have adequate levels of vitamin A.
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.
Taking vitamin A orally does not reduce the risk of developing new tumors or improve survival in people with head and neck cancer.
Taking vitamin A orally does not lower the risk of passing HIV to the fetus during pregnancy, to newborns during delivery, or to infants during breastfeeding. In fact, HIV-positive women who take vitamin A supplements during pregnancy might have an increased risk of passing HIV to their babies through breast milk.
Taking vitamin A orally does not prevent or reduce symptoms of lower airway infections in children. In fact, vitamin A is linked with a slight increase in the risk of respiratory tract infections in children.
Increased vitamin A levels in the blood or higher vitamin A intakes are associated with a lower risk of cervical cancer. However, this only works 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.
Taking vitamin A along with an anticancer drug does not improve survival in people with this cancer that starts in the bone marrow, compared to taking the anticancer drug alone. In fact, taking vitamin A along with this drug might increase the risk of toxicity.
Early research shows that taking vitamin A (retinol palmitate) can reduce rectal symptoms caused by pelvic radiotherapy.
Taking a combination supplement containing selenium, zinc, vitamin A, vitamin C, and vitamin E might reduce the recurrence of precancerous polyps in the large intestine.
Taking vitamin A alone or along with beta-carotene does not seem to prevent colorectal cancer.
Taking vitamin A might reduce the time needed in intensive care during surgery to improve blood flow to the heart. It also might reduce the time in the hospital after surgery.
Higher intake of vitamin A and beta-carotene is linked to a reduced risk of esophageal cancer. But taking vitamin A in combination with beta-carotene does not seem to prevent esophageal cancer.
Taking vitamin A alone or with beta-carotene does not seem to prevent stomach cancer.
Taking vitamin A during pregnancy may not reduce the risk of death for the mother or child. Also, vitamin A supplementation during pregnancy does not prevent HIV progression in women with HIV and low levels of vitamin A. However, giving vitamin A to HIV-positive infants and children might reduce the risk of HIV-related death.
Taking vitamin A might decrease the risk of death from diarrhea in children with vitamin A deficiency, with or without HIV.
Giving vitamin A as a shot to very low birth weight infants may reduce the risk of chronic lung disease. Giving vitamin A as a shot might also improve brain development by one year in some low birth weight infants. But it seems to work only in very small infants who are also given nitric oxide gas.
Taking vitamin A for one year decreases fatigue (tiredness) in patients with relapsing-remitting multiple sclerosis.
Taking vitamin A does not increase survival in people with lung cancer. Also, taking vitamin A with beta-carotene might increase the risk of lung cancer in smokers and people exposed to asbestos. This effect is may be due to beta-carotene. It is possible that this increased risk is linked with beta-carotene use, not vitamin A.
Taking vitamin A orally may decrease malaria symptoms in children less than 3 years-old living in areas where malaria is common. But taking vitamin A does not seem to improve symptoms or prevent death caused by of a severe form of malaria that affects brain function.
People who consume higher amounts of vitamin A in the diet seem to have a slightly lower risk of non-Hodgkin's lymphoma.
Taking vitamin A does not reduce the risk of developing ovarian cancer.
Taking vitamin A does not seem to reduce the risk of death in healthy adults.
Taking vitamin A along with beta-carotene does not seem to prevent pancreatic cancer.
Blood levels or dietary intake of vitamin A are not associated with risk of Parkinson's disease.
Taking vitamin A orally along with vitamin E seems to improve healing after laser eye surgery.
Vitamin A intake from the diet does not seem to be linked with a reduced risk of prostate cancer.