What is it?
Vitamin A is a fat-soluble 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. 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 most commonly used for treating vitamin A deficiency.
People also use vitamin A to reduce complications of diseases such as malaria, HIV/AIDS, and measles, and for fertility, diarrhea, vision, child development, skin disorders, infections, and many other conditions, but there is no good scientific evidence to support most of these uses.
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 lower risk of breast cancer. It is not known if taking vitamin A supplements has the same benefit.
- Cataracts. People who consume high amounts of vitamin A in their diet seem to have a lower risk of developing cataracts.
- Measles. Taking vitamin A by mouth seems to reduce the risk of measles complications or death in children with measles and vitamin A deficiency.
- Ability to see in low-light conditions. Taking vitamin A during pregnancy seems to reduce night blindness by 37% in malnourished women. Vitamin A might work better for this condition when taken with zinc.
- White patches inside the mouth that are usually caused by smoking (oral leukoplakia). Research shows that taking vitamin A can help treat precancerous lesions in the mouth.
- Death from any cause. Most experts agree that high-dose vitamin A supplementation reduces the risk of death in children 6-59 months of age who are at risk for vitamin A deficiency. Taking vitamin A does not seem to reduce the risk of death in healthy adults.
- Complications after childbirth. Taking vitamin A, during, and after pregancy reduces diarrhea after giving birth in malnourished women. Taking vitamin A before and during pregnancy also seems to reduce the risk of death by 40% in malnourished women.
- An inherited eye condition that causes poor night vision and loss of side vision (retinitis pigmentosa). Taking vitamin A can slow the progression of an eye disease that causes damage to the retina.
- A type of inflammatory bowel disease (ulcerative colitis). Some research shows that taking vitamin A daily for 2 months can reduce symptoms and help the intestine to heal in adults with ulcerative colitis.
Possibly Ineffective for …
- Prone to allergies and allergic reactions (atopic disease). Giving a single dose of vitamin A to infants does not seem to prevent atopy.
- A lung disease that affects newborns (bronchopulmonary dysplasia). Research shows that injecting vitamin does not reduce the risk of breathing problems in most low birth weight infants.
- Diarrhea caused by cancer drug treatment. Taking vitamin A by mouth does not seem to prevent diarrhea or mouth pain caused by chemotherapy in children.
- Death of an unborn or premature baby. Taking vitamin A supplements before, during, or after pregnancy does not seem to prevent infant death during the first year of life. Also giving vitamin A supplements to infants does not seem to prevent death.
- Infection of the intestines by parasites. Giving a single dose of vitamin A to children taking medicine to treat intestinal parasites does not seem to prevent reinfection compare to only taking the medicine.
- The most serious type of skin cancer (melanoma). Research shows that taking a high dose of vitamin A by mouth does not increase relapse-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 vitamin A does not seem to reduce pain in people with spinal osteoarthritis who have adequate levels of vitamin A. Also, taking a specific product containing selenium, vitamin A, vitamin C, and vitamin E does not appear to improve osteoarthritis symptoms.
- 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 this condition.
Probably 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 shows 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.
- Infection of the lower airways. Taking vitamin A by mouth 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.
- Pneumonia. Taking vitamin A by mouth does not help treat or prevent pneumonia in children living in developing countries.
Insufficient Evidence to Make a Determination for …
- Acne. There are some prescription vitamin A products approved by the US FDA for the treatment of acne, including Tazarotene (Tazorac) and adapalene (Differin). But these products are not the same as non-prescription vitamin A products. It’s unclear whether non-prescription vitamin A products, such as retinol, can help with acne.
- Aging skin. Early research shows that applying vitamin A (retinol) on the skin for 12 weeks improves skin color, flexibility, and wrinkles in women over 33 years of age. It isn’t clear whether retinol works as well as the prescription products that are approved by the US FDA for treating aging skin, such as tretinoin (Renova).
- Liver disease in people who drink alcohol. Early research shows that taking vitamin A together with coenzyme Q10 and other vitamins and minerals does not improve survival in people with liver disease caused by alcohol use.
- Low levels of healthy red blood cells (anemia) due to iron deficiency. 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.
- Autism. Children with autism often have low levels of vitamin A. Low levels of vitamin A have been linked with symptoms of autism. Early research shows that taking vitamin A slightly reduces some symptoms in children with autism.
- Cervical cancer. Research shows 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.
- Non-cancerous growths in the large intestine and rectum (colorectal adenoma). 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.
- A lung disease that makes it harder to breathe (chronic obstructive pulmonary disease or COPD). Early research has found that taking the recommended amounts of vitamin A is linked with less chance of developing emphysema, a type of COPD.
- Colorectal cancer. Taking vitamin A alone or along with beta-carotene does not seem to prevent colorectal cancer.
- Surgery to improve blood flow to the heart (CABG surgery). Early research shows that taking vitamin A might reduce the time needed in intensive care during this type of surgery. It also might reduce the time in the hospital after surgery.
- Cancer of the esophagus. 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.
- Stomach cancer. Taking vitamin A alone or with beta-carotene does not seem to prevent stomach cancer.
- HIV/AIDS. 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 might reduce the risk of HIV-related death.
- Diarrhea in people with HIV/AIDS. Taking vitamin A might decrease the risk of death from diarrhea in children with vitamin A deficiency, with or without HIV. But conflicting results exist.
- Infant development. Giving vitamin A as a shot to very low birth weight infants seems to reduce the risk of chronic lung disease by about 13%. 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.
- Fatigue in people with multiple sclerosis (MS). Early research shows that taking vitamin A for one year decreases fatigue (tiredness) in patients with relapsing-remitting multiple sclerosis.
- Cancer of the white blood cells (leukemia). Early research shows that taking vitamin A along with an anticancer drug does not improve survival in people with this condition compared to taking the anticancer drug alone. In fact, taking vitamin A along with this drug might increase the risk of toxicity.
- Liver cancer. People who take vitamin A supplements, or those with higher blood levels of vitamin A, don’t seem to have a lower risk of liver cancer.
- Lung Cancer. Most research suggests that 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. But it’s not clear if this effect is due to beta-carotene. It’s possible that this increased risk is linked with beta-carotene use, not vitamin A.
- 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. 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.
- Cancer that starts in white blood cells (non-Hodgkin lymphoma). People who consume higher amounts of vitamin A in the diet seem to have a slightly lower risk of non-Hodgkin lymphoma.
- Ovarian cancer. Early research has found that taking vitamin A is linked to reduced risk of developing ovarian cancer.
- Pancreatic cancer. Taking vitamin A along with beta-carotene does not seem to prevent pancreatic cancer.
- Parkinson disease. Early research suggests that blood levels or dietary intake of vitamin A are not associated with risk of Parkinson disease.
- Recovery from laser eye surgery (photoreactive keratectomy). Taking vitamin A by mouth along with vitamin E seems to improve healing after laser eye surgery.
- Prostate cancer. Vitamin A intake from the diet does not seem to be linked with a reduced risk of prostate cancer.
- Scaly, itchy skin (psoriasis). Tazarotene (Tazorac) is a prescription-only vitamin A product that is approved by the US FDA for this condition. But these products are not the same as non-prescription vitamin A products. It’s unclear whether non-prescription vitamin A products, such as retinol, can help with this condition.
- Inflammation and damage to the rectum due to radiation therapy. Early research shows that taking vitamin A (retinol palmitate) can reduce rectal symptoms caused by pelvic radiotherapy.
- An eye disorder in premature infants that can lead to blindness (retinopathy of prematurity). Early research shows that giving vitamin A to preterm infants reduces the risk of retinopathy of prematurity.
- Skin cancer. Early research has found that consuming more vitamin A in the diet is linked to a lower risk for skin cancer.
- Infections of the kidney, bladder, or urethra (urinary tract infections or UTIs). Early research shows that taking vitamin A daily for 10 days along with antibiotics can help girls 2-12 years old who have an infection of the kidney to recover faster.
- Skin wrinkles from sun damage. Early research shows that applying vitamin A (retinol) serum to the skin improves skin smoothness and wrinkles in women with sun-damaged skin. It isn’t clear if retinol work as well as the prescription products that are approved by the FDA for treating skin wrinkles, such as tretinoin (Renova).
- An eye disease that leads to vision loss in older adults (age-related macular degeneration or AMD).
- A group of eye disorders that can lead to vision loss (glaucoma).
- Improving immune function.
- Preventing and speeding recovery from infections.
- Promoting good vision.
- Hay fever.
- Wound healing.
- Other conditions.
More evidence is needed to rate vitamin A for these uses.
Vitamin A is POSSBILY UNSAFE when taken by mouth in doses greater than 10,000 units (3,000 mcg) daily. Some 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 also 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.
When applied to the skin: Vitamin A is POSSIBLY SAFE when used on the skin, short-term. Retinol 0.5% serum has been used daily for up to 12 weeks without serious side effects.
When given as a shot: Vitamin A is LIKELY SAFE when given as a shot into the muscle in amounts less than 10,000 units (3,000 mcg) daily.
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 (3,000 mcg) of pre-formed vitamin A 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.
Children: 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 (600 mcg)/day in children up to 3 years old.
- Less than 3000 units (900 mcg)/day in children ages 4 to 8 years old.
- Less than 5667 units (1700 mcg)/day in children ages 9 to 13 years old.
- Less than 9333 units (2800 mcg)/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.
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.
Iron deficiency: Iron deficiency might affect the body’s ability to breakdown and use vitamin A.
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.
Antibiotics (Tetracycline antibiotics)
Interaction Rating=Moderate Be cautious with this combination.
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. But taking normal doses of vitamin A along with tetracyclines doesn’t 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 for skin conditions (Retinoids)
Interaction Rating=Major Do not take this combination.
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.
Medications that can harm the liver (Hepatotoxic drugs)
Interaction Rating=Moderate Be cautious with this combination.
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.
Interaction Rating=Moderate Be cautious with this combination.
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.
- General: The Recommended Dietary Allowance (RDA) levels for vitamin A are 900 mcg daily for men and 700 mcg daily for women. For women who are pregnant, the RDA is 770 mcg daily. For women who are breast-feeding, the RDA is 1,300 mcg daily.
- For white patches inside the mouth that are usually caused by smoking (oral leukoplakia): Weekly dose of 200,000-300,000 IU of vitamin A has been used for 6-12 months.
- For complications after childbirth: Weekly doses of 23,000 IU of vitamin A have been used before, during, and after pregnancy. Also, weekly doses of 23,300 IU of vitamin A have been used before and during pregnancy.
- For ability to see in low-light conditions: To prevent this condition in pregnant women, weekly doses of 23,000 IU of vitamin A have been used before, during, and after pregnancy. In women with low levels of zinc, taking it in combination with 35 mg of zinc daily seems to work best.
- For an inherited eye condition that causes poor night vision and loss of side vision (retinitis pigmentosa): Daily doses of 15,000 IU of vitamin A, sometimes along with 400 IU of vitamin E daily, has been used.
- A type of inflammatory bowel disease (ulcerative colitis): Vitamin A 25,000 IU daily has been used for 2 months.
The tolerable Upper Intake Level (UL) for vitamin A is 10,000 units (3,000 mcg) daily. The UL is the highest level of intake that is likely to pose no risk of harmful effects. The UL for vitamin A is for preformed vitamin A (retinol) and does not include provitamin A carotenoids.
Vitamin A dosage is most commonly expressed in IU, but dosing 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.
- General: Recommended Dietary Allowance (RDA) levels of vitamin A are: birth to 6 months, 400 mcg/day; 7 to 12 months, 500 mcg/day; 1 to 3 years, 300 mcg/day; 4 to 8 years, 400 mcg/day; 9 to 13 years, 600 mcg/day; 14-18 years, 900 mcg/day. For girls 14-18 years of age who are pregnant, the RDA is 750 mcg. For girls 14-18 years of age who are lactating, the RDA is 1,200 mcg.
- For measles: 100,000 to 200,000 IU of vitamin A for at least two doses has been used in children less than 2 years-old.
- For death of an unborn or premature baby: Vitamin A supplements are recommended for children 6-59 months of age who are at risk of vitamin A deficiency. For children ages 6-11 months, one dose providing 100,000 IU of vitamin A is recommended. For children ages 12-59 months, 200,000 IU of vitamin A every 4-6 months in recommended.
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. For birth to 3 years, 600 mcg/day (2,000 units); 4 to 8 years, 900 mcg/day (3,000 units); 9 to 13 years, 1700 mcg/day (5,667 units); and 14 to 18 years, 2800 mcg/day (9,333 units).
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