Vitamin D status and skin phototype in a general adult population in France

Introduction. A link between bone mineral density and skin color has been r eported recently, and pigmentation has been shown to affect cutaneous vitam in D production. In the present study, we investigated the relationship bet ween phototype, global self assessed sun exposure, geographical location an d vitamin D serum levels in 1191 French adults. Methods. Three multiple linear regression analyses were performed. The two first analyses to test separately the effect of phototype, and the effect o f sun exposure on the Vitamin D levels. Then, a third model was constructed , using both factors and geographical location. Results. When the factors were analyzed separately, individuals with lower phototype showed significantly lower levels of vitamin D than those with da rker phototype, as well as, individuals with lower sun exposure showed sign ificantly lower levels of vitamin D than those with higher sun exposure. Ho wever in the global model, which takes into account phototype and sun expos ure simultaneously together with the region of residence, the vitamin D sta tus was no longer linked with the phototype, but with sun exposure and geog raphical location. Conclusion. Since phototype and global self-assessment of sun exposure were positively linked, our data suggest that lower vitamin D levels in fair-sk inned individuals are due to their sun exposure behavior.