The a-B-C-ds of sensible sun protection

Abstract

Ultraviolet (UV) radiation is a carcinogen that also compromises skin appearance and function. Since the UV action spectra for DNA damage, skin cancer, and vitamin D photosynthesis are identical, and vitamin D is readily available from oral supplements, why has sun protection become controversial? First, the media and, apparently, some researchers are hungry for a new message. They have also drawn attention to the emerging evidence of possible vitamin D benefits other than for bone health. Second, the controversy is fueled by a powerful special interest group: the tanning industry. This industry does not target the frail elderly or inner-city ethnic minorities, which are the groups at greatest risk of vitamin D deficiency, but rather fair-skinned teenagers and young adults, who are at highest risk of UV photodamage. Third, evolution does not keep pace with civilization. When nature gave humans the appealing capacity for cutaneous vitamin D photosynthesis, life expectancy was less than 40 years of age; long-term photodamage was not a concern, and vitamin D deficiency, with its resulting skeletal abnormalities (rickets), was likely to be fatal in early life. This article briefly reviews the pseudo-controversy , as well as the data supporting a revision of the recommendations for vitamin D supplementation. It concludes with a suggested message for patients, many of whom are understandably confused by recent media coverage of the topic.