Carotenoids comprise a diverse class of antioxidant molecules that help protect the body from oxidative damage. Approximately 700 natural carotenoids have been isolated and characterized. Most are derived from plants, where they serve multiple functions: photosynthetic pigments, photoprotectants, and free radical scavengers. Some 50-60 carotenoids are present in a typical diet, with the major sources being fruits and vegetables.
 
Beta-carotene/vitaminA is the best known of the carotenoids because: (1) it is one of the most abundant in a typical adult diet, and (2) it provides a dual nutritional function. In addition to its role as an antioxidant, the body converts beta-carotene into vitamin A.
 
Other members of the antioxidant carotenoid family include cryptoxanthin, alpha-carotene, zeaxanthin, lutein, and lycopene. However, unlike beta-carotene, most of these nutrients are not converted to vitamin A in significant amounts.