Released March 31, 2009
STILLWATER, Okla. – Vitamin A has many functions to keep your body healthy.
Janice Hermann, Oklahoma State University Cooperative Extension nutrition specialist, said vitamin A can be provided from both animal and plant foods.
“Animal foods are a source of preformed vitamin A that is ready to be used by the body,” she said. “Plant foods are a source of carotenoids, most notably beta-carotene, which the body can change into vitamin A.”
The functions of vitamin A include helping to:
- Promote vision.
- Keep the skin healthy.
- Keep the lining of the mouth, nose, throat, digestive, respiratory and urinary tracts healthy.
- Support growth and reproduction.
Beta-carotene can function as an antioxidant in addition to the other functions of vitamin A.
Hermann said because vitamin A is stored in the body a deficiency doesn’t appear until body stores are depleted. Vitamin A deficiency is uncommon in the United States but it is still a major problem in many other countries. People who don’t get enough vitamin A can experience night blindness, total blindness, skin problems and increased risk of infections.
“Food sources of vitamin A include liver, egg yolk and dairy products fortified with vitamin A,” she said. “Many ready-to-eat cereals are also fortified with vitamin A.”
Carotenoids, like beta-carotene, are found in dark-green leafy vegetables such as spinach and broccoli and in deep orange vegetables and fruits such as carrots, sweet potatoes, cantaloupe and apricots.
The daily recommended vitamin A intakes are:
- Men 19 years and older; 900 micrograms retinol activity equivalents (RAE).
- Women 19 years and older; 700 micrograms RAE.
- Women 19 years and older, who are pregnant; 770 micrograms RAE.
- Women 19 years and older who are breastfeeding; 1,300 micrograms RAE.
Although daily recommended intakes are expressed as RAE, many food and supplement labels use international units (IU), an old measure, to report the amount of vitamin A activity. For comparison, 1,000 IU is approximately 300 micrograms RAE.
Hermann said do not get more than 3,000 micrograms preformed vitamin A from foods and supplements. Excessive vitamin A, usually from supplements not food, can be harmful. Over time, excessive vitamin A may contribute to osteoporosis by weakening the bones. In addition, excessive vitamin A in early pregnancy may also pose a risk for birth defects. Although not harmful, too much beta-carotene from food can turn the skin yellow. However, excessive beta-carotene from supplements can act as a prooxidant instead of an antioxidant and may be harmful.
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http://www.dasnr.okstate.edu/Members/katie.reim-40okstate.edu/remember-your-vitamin-a
Contact: Katie Reim, 405-744-6792, katie.reim@okstate.edu
