Vitamin A

Definition

Vitamin A is a fat-soluble vitamin.

Alternative Names

Function

Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucous membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye.

Vitamin A promotes good vision, especially in low light. It may also be need for reproduction and breast feeding.

Retinol is an active type of vitamin A. It is found in animal liver, whole milk, and some fortified foods.

Carotenoids are dark colored dyes found in plant foods that can turn into a form of vitamin A. One such carotenoid is beta-carotene. Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by unstable substances called free radicals. Free radicals are believed to contribute to certain chronic diseases and play a role in the degenerative processes seen in aging.

References

Ford MD, Clinical Toxicology. 1st ed. Philadelphia, Pa: WB Saunders; 2001:297

Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press, Washington, DC, 2001.