Evaluation of the Photoprotective Effect of Oral Vitamin E Supplementation

Abstract

Solar-induced cutaneous damage is mediated partly via oxidative pathways. Some evidence exists for a photoprotective role of antioxidants. In a double-blind, placebo-controlled study, we examined the effect of a long-term, orally administered antioxidant against UV-induced epidermal damage. Healthy human subjects supplemented their usual diet daily with either 400 IU of oral vitamin E (alpha-tocopherol acetate) or placebo over a 6-month period. Minimal erythema dose and histologic response to threefold minimal erythema dose exposure were determined at baseline, 1 month, and 6 months. The minimal erythema dose did not vary substantially at the three time points within each treatment group or in the vitamin E-supplemented group vs the placebo group. The number of sunburn cells produced by a threefold minimal erythema dose exposure was also not significantly different between the two groups. Of note, however, vitamin E levels in plasma increased only modestly and in skin biopsy specimens were unchanged following 1 month and 6 months of supplementation. No clinical or histologic difference in the response to UVB could be detected between the placebo and vitamin E-supplemented groups. In this small study, daily ingestion of 400 IU of oral alpha-tocopherol daily does not provide meaningful photoprotection.