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Vitamin A Requirements and Dietary Sources

Vitamin Guide

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Updated February 05, 2014

Carrots and beta carotene

Carrots are a great source of beta-carotene, a precursor of vitamin A.

Pat Herman

Vitamin A is a member of the fat-soluble family of vitamins that also includes vitamin D, vitamin E and vitamin K.

It's important for normal vision, adequate growth, and for cell division and differentiation. It's essential for immune system function because it is necessary for the production of white blood cells that help fight infections. You also need vitamin A for healthy skin and mucous membranes.

Vitamin A deficiency is rarely seen in developed countries, but can result in visual problems and loss of normal immune system function.

Daily Requirements

Males

1 to 3 years: 300 micrograms of retinol activity equivalents (mcg RAE) per day
4 to 8 years: 400 mcg RAE per day
9 to 13 years: 600 mcg RAE per day
14+ years: 900 mcg RAE per day

Females

1 to 3 years: 300 mcg RAE per day
4 to 8 years: 400 mcg RAEs per day
9 to 13 years: 600 mcg RAE per day
14+ years: 700 mcg RAE per day

Vitamin A is found in both plant and animal sources. Preformed vitamin A, or retinol, is found in butter, egg yolks, fish, liver, meats and whole milk. Plant sources of vitamin A are called provitamin A carotenoids and include beta-carotene, alpha-carotene, and beta-cryptoxanthin. Carotenoids are found in dark green and yellow vegetables, as well as orange fruits and vegetables.

Taking vitamin A supplements, such as beta-carotene, has been recommended for preventing cancer;. But there's no evidence for this recommendation. In the case of cigarette smokers, taking beta-carotene supplements may increase risk of cancer.

Taking large doses of preformed vitamin A supplements for extended periods of time may result in vitamin A toxicity, so the Institute of Medicine determined tolerable upper levels to be 3,000 mcg RAE per day. Vitamin A toxicity may result in birth defects, liver abnormalities, and reduced bone mineral density that may result in osteoporosis.

Also Known As: Retinol, carotenoids

Sources:

"Vitamin A." Accessed March 17, 2009. http://ods.od.nih.gov/factsheets/vitamina/

Otten JJ, Hellwig JP, Meyers LD. "Dietary Reference Intakes: The Essential Guide to Nutrient Requirements." IOM, 2006.

 

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