The carotenoid plant pigment beta carotene is also a powerful antioxidant. There have been claims that taking beta carotene supplements can help prevent cancer and heart disease and boost a one's immune system.
The results of research investigating these claims have been mixed. However, two high-quality medical studies showed that male smokers who take beta carotene supplements (even small amounts in the range of 30 milligrams per day) had an increased risk of lung cancer.
Thus, most medical experts advise that people get their beta carotene from eating vegetables rather than from supplement pills.