ABSTRACT
Beta-carotene is the major provitamin A carotenoid of nutritional relevance followed by alpha-carotene, lycopene, beta-cryptoxanthin, lutein, zeaxanthin and others from more than 600 known carotenoids taken up from fruit and vegetables. About 50 to 60 of these have provitamin A activity (1,2). The bioavailability of beta-carotene is highly variable and depends on various factors like the amount of carotenoids, the food source, dietary factors like fat content and type as well as inter-individual differences in absorption (3-5). There was no evidence of toxicity found so far (6). The uptake of carotenoids by the skin might additionally be influenced by cigarette smoking and UV-light (7,8).
