Examples of carotenoids include beta carotene, alpha carotene, gamma carotene, beta zeacarotene, cryptoxanthin, lycopene, zeaxanthin, lutein, canthaxanthin, crocetin, capsanthin).

Function: There are over 600 identified carotenoids. Approximately 50 act as precursors to vitamin A. Carotenoids are potent antioxidants, help with immune function, and are involved with the growth and the repair of tissues.

Sources: Yellow vegetables (carrots, pumpkins, squash, sweet potatoes); green ­ vegetables (broccoli, peas, collard greens, endive, kale, lettuce, peppers, spinach, turnip greens); fruits (apricots, cantaloupe, papaya, peaches, watermelon, cherries, tomatoes)

RDA: None established

Optimal Intake: 5,000 to 25,000 IU of mixed carotenoids

Deficiency Signs: Increased susceptibility to developing certain cancers and cardiovascular disease

Toxicity: Relatively nontoxic. Too high of an intake can lead to carotenemia (yellowing of skin), which disappears after reduction of carotenoid intake.