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Dosing
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.
Sources of Vitamin A
Vitamin A is found in dairy products, fish, darkly colored fruits and vegetables. Consumption of five servings of fruits and vegetables per day supplies 5-6 milligrams per day of provitamin A carotenoids, which provides about 50-65% of the adult RDA for vitamin A.
Adults (over 18 years old)
Vitamin A is included in most multivitamins, often in 5,000 IU doses as softgels, capsules, tablets, or liquid. U.S. Recommended Daily Allowance (RDA) for adults have been established by the U.S. Institute of Medicine of the National Academy of Sciences. Recommendations are: 900 micrograms per day (3,000 IU) for men and 700 micrograms per day (2,300 IU) for women. For pregnant women 19 years and older, 770 micrograms per day (2,600 IU) is recommended. For lactating women 19 years and older, 1,300 micrograms per day (4,300 IU) is recommended.
For vitamin A deficiency not involving xerophthalmia, 100,000 IU orally or intramuscularly administered daily for three days, followed by 50,000 IU per day for two weeks has been used. A maintenance dose of 10,000 to 20,000 IU per day for two months has been recommended.
Supporting care following chemotherapy may include weekly injections of 100,000 IU 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 (RDA) have been established by the U.S. Institute of Medicine of the National Academy of Sciences. Recommendations are: for children 1-3 years-old, 300 micrograms per day (1,000 IU); for children 4-8 years-old, 400 micrograms per day (1,300 IU); and for children 9-13 years-old, 600 micrograms per day (2,000 IU). For pregnant women between 14-18 years-old, 750 micrograms per day (2,500 IU) is recommended; for lactating women between 14-18 years-old, 1,200 micrograms per day (4,000 IU) is recommended.
The World Health Organization (WHO) has established dosage guidelines for children between 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.
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Portions of this document last updated:Sept. 1, 2009
THE NATURAL STANDARD RESEARCH COLLABORATION
(www.naturalstandard.com)
