The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
Vitamin A is found in dairy products, fish, and darkly colored fruits and vegetables. Consumption of five servings of fruits and vegetables daily supplies 5-6 milligrams daily of provitamin A carotenoids, which provides about 50-65% of the adult recommended dietary allowance (RDA) for vitamin A.
Vitamin A is included in most multivitamins, often in 5,000 IU doses as softgels, capsules, tablets, or liquid. U.S. RDAs for adults have been established by the U.S. Institute of Medicine of the National Academy of Sciences. The recommendations are as follows: 900 micrograms daily (3,000 IU) for men and 700 micrograms daily (2,300 IU) for women. For pregnant women 19 years old and older, 770 micrograms daily (2,600 IU) is recommended. For lactating women 19 years old and older, 1,300 micrograms daily (4,300 IU) is recommended.
For vitamin A deficiency not involving xerophthalmia, the following has been used: 100,000 IU by mouth or injected into the muscle daily for three days, followed by 50,000 IU daily for two weeks. A maintenance dose of 10,000-20,000 IU daily for two months has been recommended.
For community-based in intervention, 200,000 IU has been taken as a single dose by mouth monthly for six months.
For acute promyelocytic leukemia (treatment), all- trans retinoic acid (Vesanoid® (tretinoin)) has been administered as follows: 45 milligrams per square meter of body surface area daily by mouth, as two evenly divided doses until complete remission; therapy should be discontinued 30 days after the achievement of complete remission or after 90 days of treatment, whichever occurs first.
For HIV, vitamin A (400,000 IU in adults and 50,000 IU in infants) has been given to women and infants by mouth during the postpartum period for two years.
For mortality reduction, 1,333-200,000 IU has been taken by mouth daily or on alternate days for 28 days to 12 years.
For oral leukoplakia, 300,000 IU has been taken by mouth weekly for 12 months or 200,000 IU has been taken by mouth weekly for six months or 1-2 milligrams of 13- cis -retinoic acid per kilogram of body weight has been taken by mouth daily for three months. Topical 0.1% isotretinoin gel three times daily for four months or a topical formulation of 20 milligrams of acitretin daily in a two-layer mucoadhesive tablet has been used.
For retinitis pigmentosa, the National Eye Institute (NEI) recommends that patients with typical forms receive 15,000 IU of supplemental vitamin A palmitate daily under medical supervision.
For tuberculosis, 5,000-200,000 IU has been taken three times by mouth prior to antituberculosis medication.
For UV-induced skin damage, topical all- trans retinoic acid (tretinoin, the acid form of vitamin A), at a concentration of 0.02% or higher, has been used over a period of 4-11 months.
Supporting care following chemotherapy may include weekly injections of 100,000 IU of vitamin A. Patients receiving vitamin A should be observed carefully for liver toxicity.
Injections should always be performed by a licensed healthcare provider.
Children (under 18 years old)
Recommended dietary allowances (RDAs) have been established by the U.S. Institute of Medicine of the National Academy of Sciences. The recommendations are as follows: for children 1-3 years old, 300 micrograms (1,000 IU) daily; for children 4-8 years old, 400 micrograms (1,300 IU) daily; and for children 9-13 years old, 600 micrograms (2,000 IU) daily. For pregnant women 14-18 years old, 750 micrograms (2,500 IU) daily is recommended. For lactating women 14-18 years old, 1,200 micrograms (4,000 IU) daily is recommended.
The World Health Organization (WHO) has established dosage guidelines for children 6-11 months old to receive 100,000 IU of vitamin A. This increases to 200,000 IU every six months from 12 to 59 months of age.
For anemia, 3,000 micrograms of vitamin A has been taken by mouth daily for two months.
For bronchopulmonary dysplasia in premature infants, 2,000 IU on alternate days to 4,000 IU three times weekly by mouth has been taken.
For childhood growth promotion, 60 milligrams of vitamin A has been taken for up to six months.
For cystic fibrosis, the 2002 cystic fibrosis guidelines recommend vitamin A supplements for all children with cystic fibrosis and pancreatic insufficiency, specifically 3,000 micrograms of retinol activity equivalents (RAEs) daily for children over the age of eight years.
For infant mortality, the following has been taken: three milligrams by mouth daily from 18 to 28 weeks' gestation; 7,000 micrograms by mouth once weekly during gestation; 5,000-10,000 IU daily by mouth from 12-24 weeks' gestation; 200,000 IU weekly, or 200,000 IU at time of delivery; and 200,000-400,000 IU daily by mouth postpartum. A dose of 2,000 IU has been taken every two days for 28 days, injected into the muscle of infants. Also injected into the muscle, 4,000 IU every two days or 3,750 IU every two days for 16 days has been used. Doses between 1,500 and 5,000 IU, by mouth or injected into the muscle of the infant, have been used every other day or three times weekly. Doses from 8,333 IU weekly to 200,000 IU every six months by mouth have been used.
For malaria, children aged 6-60 months were given one capsule (or half a capsule if younger than 12 months) of 200,000 IU of vitamin A (in 200 microliters of peanut oil with 10 micrograms of vitamin E as a preservative) every three months for 13 months.
For measles, the World Health Organization (WHO) recommends 200,000 IU daily by mouth for two days for children with measles who live in areas of vitamin A deficiency. For infants with measles, the WHO recommends 100,000 IU daily by mouth for two days.
For childhood mortality, does from 8,333 IU weekly to 200,000 IU every six months by mouth have been used. Doses from 10,000 IU weekly for 40 weeks to 206,000 IU once very four months, for up to six doses, have been used.
For HIV, a large dose of vitamin A (400,000 IU in adults and 50,000 IU in infants) has been given to women and infants during the postpartum period for two years.
For xerophthalmia (dry eye), the World Health Organization (WHO) recommends 200,000 IU daily by mouth immediately on diagnosis, 200,000 IU on the following day, and then 200,000 IU prior to discharge, or if clinical deterioration occurs, or 2-4 weeks later. Infants under 12 months of age and very small and very-low-weight children should be given half the dosage.