Effects of Controlled Exposure of Sunlight on Plasma and Skin Levels of β-Carotene

Abstract

We conducted a randomized placebo-controlled double-blind study in 20 healthy young female students (skin type II + III, body mass index 18–22) in order to evaluate the efficacy of 10 weeks of moderate dose (30 mg/d) β-carotene (BC) on plasma and skin β-carotene levels during 12 days of time and intensity controlled sunlight exposure at sea level (30″ latitude, Red Sea, Eilath, Israel). After 12 days of controlled sun exposure (total UV dose of about 10.000 J/cm²), plasma β-carotene decreased in the placebo (p<0.01) and β-carotene group (not significant). In addition cutaneous β-carotene decreased significantly in both groups. Plasma a-tocopherol decreased significantly (p<0.01) during exposure time in both groups. In the supplemented group, however, the decrease of a-tocopherol was significantly greater (p<0.01) than in the placebo group. We conclude that sunlight influences the β-carotene and α-tocopherol content of blood and tissues.

Key Words:

• β-carotene
• α-tocopherol
• human skin
• free radicals
• UV-light