Vitamin A is a group of compounds. As explained by the National Institutes of Health Office of Dietary Supplements, vitamin A from animal sources is called preformed vitamin A, and absorbs as retinol, which can then be converted to other forms of vitamin A, such as retinoic acid. Vitamin A from plant sources is referred to as provitamin A carotinoid, which is converted to retinol in the body. Widely known carotenoids include alpha and beta-carotene. Vitamin A is necessary for healthy vision and bones, along with immune system and cell function.
Liver
Vitamin A is stored in the liver, so in animal sources, the liver is where it is found in highest concentration. The National Institutes of Health reports that the recommended daily allowance, or RDA, for vitamin A is 3,000 IUs, or international units, for adult men and 2,310 IUs for adult women. Lactating women should consume 4,300 IUs. Eating a 3-oz. portion of liver will more than cover the daily requirement of vitamin A, as it provides 27,185 IUs, while a 3-oz. serving of chicken liver provides 12,325. Fish liver oil also contains a high amount of vitamin A, according to a University of California at Berkely report, although there is little vitamin A in the flesh of the fish.
Carrots
Carrots are a rich source of provitamin A in the form of beta-carotene, the carotenoid that gives carrots their deep orange color. Carrots come in other colors as well, from white to deep orange and purple, according to Texas A&M University. World's Healthiest Foods explains that carrots contain other carotenoids as well, including alpha-carotene, which works together with beta-carotene to offer health benefits including cancer prevention and regulation of blood sugar. A 1/2 cup serving of boiled carrot slices contains 13,418 IU of vitamin A, which is more than four times higher than the recommended RDA, according to the NIH.
Leafy Greens
Leafy green vegetables are rich in color, even though it's not orange. Leafy greens include spinach and kale, both with high concentrations of vitamin A. Researchers at the U.S. Department of Agriculture Human Nutrition Research Center at Tufts University in Boston examined the effects of the consumption of yellow and green leafy vegetables on vitamin A status in school children. The results of the study, published in the April 2007 issue of the "American Journal of Clinical Nutrition," show that consumption of leafy greens, with minimal additional fat, such as butter, increases the body's vitamin A content and can normalize low levels of vitamin A in the liver. A 1/2 cup of boiled spinach contains 11,458 IUs and 1 cup of raw spinach contains 2,813, while 1/2 cup of boiled kale contains 9,558 IUs.
Cantaloupe
Few fruits are rich in vitamin A, except for cantaloupe. One cup of cubed cantaloupe contains 5,411 IUs of vitamin A. There are a few other fruits that offer vitamin A in much smaller amounts, including apricots, papaya, mangoes and peaches, according to the NIH. To show the vast difference in vitamin A content of cantaloupe with other fruits, one peach contains 319 IUs, compared to the 5,411 of the cantaloupe serving.
References
- National Institutes of Health Office of Dietary Supplements: Vitamin A
- University of California Berkeley: Wellness Guide To Dietary Supplements: Vitamin A
- Texas A&M University: Carrots for Valuable Vitamin A
- "American Journal of Clinical Nutrition"; Carotene-rich plant foods ingested with minimal dietary fat enhance the total-body vitamin A pool size; J.D. Ribaya-Mercado, et. al.; April 2007
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