Risks with High Doses

Carotenoids are believed to be safe at fairly high doses. Some areas of skin may become orange or yellow in color (carotenodermia) if high doses of -carotene (30 mg/day or greater) are taken for long periods but will return to normal when intake is reduced [6]. This effect can be used therapeutically in clinical practice to treat patients with erythropoietic photoporphyria (a photosensitivity disorder). Such patients have been treated with doses of approximately 180 mg/day without reports of toxic effects [6]. Carotenes have enhanced bioavailability and have been associated with an increased risk of lung cancer in smokers.

Interactions with other nutrients: Carotenoids require bile acids in order to be absorbed. Conversion of carotenoids to vitamin A requires protein, thyroid hormone, zinc, and vitamin C.