Alpha-carotene is a provitamin A carotenoid present in fruits and vegetables. Higher serum concentrations of α-carotene have been associated with lower risk of cancer and all-cause mortality. It was suggested that genetic variants influence serum concentrations of provitamin A. Recently was found, that α-carotene effectively inhibits Lewis lung carcinoma (LLC) metastasis and suppresses lung metastasis in combination with taxol in LLC-bearing mice, suggesting that Alpha-carotene could be used as an anti-metastatic agent or as an adjuvant for anti-cancer drugs.

Beta-carotene is found in many foods and is sold as a dietary supplement. Beta-carotene is a carotenoid, weak antioxidant; precursor of vitamin A, which is essential for vision and growth. Used to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (EPP). Has been used in high-dose antioxidant supplements containing ascorbic acid and vitamin E with zinc in high-risk patients with age-related macular degeneration. Beta-carotene is also used to decrease asthma symptoms caused by exercise; to prevent certain cancers, heart disease, cataracts; and to treat AIDS, alcoholism, Alzheimer’s disease, depression, epilepsy, headache, heartburn, high blood pressure, infertility, Parkinson’s disease, rheumatoid arthritis, schizophrenia, and skin disorders including psoriasis and vitiligo.