Sun-seeking behavior to increase cutaneous vitamin D synthesis: when prevention messages conflict.

Objectives: The public has long been encouraged to engage in sun-safe practices to minimize exposure to sunlight, the major cause of nonmelanoma skin cancer. More recently, some have advocated unprotected sun exposure to increase cutaneous synthesis of vitamin D as a way to promote health. We assessed the net result of these conflicting messages.

Methods: In a cross-sectional survey in 2007, questionnaires were mailed to participants of an ongoing cohort study in Washington County, Maryland. The study population consisted of 8,027 adults (55% response rate).

Results: Thirty percent of respondents were aware that unprotected sun exposure increased endogenous vitamin D levels. Among those who were aware of this benefit, 42% reported going out into the sun to increase vitamin D levels. Sun-seeking to increase vitamin D production did not significantly differ according to self-reported personal history of skin cancer, but was significantly higher among women, older age groups, those with less education, and vitamin D supplement users.

Conclusion: A substantial proportion of respondents reported sun-seeking behavior expressly to increase endogenous vitamin D levels. The message about sun exposure and vitamin D is reaching the general public; however, this finding poses challenges to skin cancer prevention efforts.