Definition of Carotenoid

Carotenoid: One of a group of compounds that includes beta-carotene, alpha-carotene, and beta-cryptoxanthin which are converted to vitamin A and are referred to as provitamin A carotenoids. The sole known role of carotenoids is to act as a source of vitamin A in the diet. Fruits and vegetables are the main source of carotenoids in the human diet.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=22370
Last Editorial Review: 6/14/2012