Vitamin A is the name of a group of fat-soluble retinoid, including retinol, retinal, retinoic acid, and retinyl esters. Vitamin A is involved in immune function, vision, reproduction, and cellular communication. Vitamin A, also called retinol, helps your eyes adjust to light changes when you come in from outside and also helps keep your eyes, skin and mucous membranes moist. Two forms of vitamin A are available in the human diet:-

1. Preformed vitamin A. Preformed vitamin A is found in foods from animal sources, including dairy products, fish, and meat (especially liver). Preformed vitamin A is efficiently absorbed and utilized by humans at absorption rates of 70–90%.
2. Provitamin A carotenoids . The most important provitamin A carotenoid is beta-carotene; other provitamin A carotenoids are alpha-carotene and beta-cryptoxanthin. The body converts these plant pigments into vitamin A. Both provitamin A and preformed vitamin A must be metabolized intracellularly to retinal and retinoic acid, the active forms of vitamin A, to support the vitamin’s important biological functions. Provitamin A carotenoids such as beta-carotene are generally considered safe because they are not associated with specific adverse health effects

 Recommended Dietary Allowances (RDAs) for Vitamin A 

             Selected Food Sources of Vitamin A

*DV = Daily Value. . Foods providing 20% or more of the DV are considered to be high sources of a nutrient.