The determinants of serum vitamin D levels in participants in a melanoma case–control study living in a temperate climate

Abstract

Sun exposure was associated with increased vitamin D levels, but levels more than 60 nmol/L were reached on average only in individuals reporting lengthy exposure (≥12 h/weekend). The sun-sensitive individuals did not achieve optimal levels without supplementation, which therefore should be considered for the majority of populations living in a temperate climate and melanoma patients in particular. Inherited variation in genes such as GC is a strong factor, and carriers of variant alleles may therefore require higher levels of supplementation.