 | | | | Medical Health Encyclopedia | |
Vitamin A
Definition:
Vitamin A is a fat-soluble vitamin. Alternative Names:
Retinol; Carotenoids Text Continues Below
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 generates the pigments in the retina. Vitamin A promotes good vision, especially in dim light. It may also be required 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.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
|
.gif)
