Vitamin A

Vitamin A is the generic name used for a group of naturally occurring molecules called retinoids. The body uses vitamin A for the maintenance of healthy skin, good vision, and a robust immune system.

Vitamin A is essential to overall good health and individuals that do not get an adequate amount of vitamin A in their diet have been shown to be more vulnerable to infection and infectious diseases, including AIDS, measles, bronchitis, yeast infections, and boils or abscesses.

A deficiency in vitamin A could also lead to a variety of skin disorders; such as psoriasis, rashes, rosacea, and warts; and to night blindness or overall decrease in the quality of vision.

Other symptoms of vitamin A deficiency include loss of taste or smell, distorted color vision, dry eyes, loss of appetite, and poor balance.

Retinol, the active form of vitamin A, is rarely found in food. Instead, the body converts other substances found in the diet into vitamin A. These substances are called precursors to vitamin A.

One such precursor is fatty acid retinyl ester, commonly found in egg yolks, liver, fish oil, whole milk and butter (some brands of reduced-fat milk, margarine, and breakfast cereal are also fortified with vitamin A).

Another precursor to vitamin A is found in the carotinoid beta-carotene. Fruits and vegetables that appear bright orange or yellow in color, such as carrots, squash, yams, cantaloupe, watermelon, apricots, and mangoes, are high in beta-carotene.

All green vegetables, such as spinach, broccoli, kale, asparagus, etc., are also a good source of carotenoids.

From:   [http://www.vitaminstuff.com/vitamin-a.html]