[Vitamin D concentrations in blood and skin phototype in a general adult population in France].

Introduction: A link between bone mineral density and skin color has been reported recently, and pigmentation has been shown to affect cutaneous vitamin D production. In the present study, we investigated the relationship between phototype, global self assessed sun exposure, geographical location and 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 of 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 darker phototype, as well as, individuals with lower sun exposure showed significantly lower levels of vitamin D than those with higher sun exposure. However in the global model, which takes into account phototype and sun exposure simultaneously together with the region of residence, the vitamin D status was no longer linked with the phototype, but with sun exposure and geographical location.

Conclusion: Since phototype and global self-assessment of sun exposure were positively linked, our data suggest that lower vitamin D levels in fair-skinned individuals are due to their sun exposure behavior.