Case-control study of melanoma and dietary vitamin D: implications for advocacy of sun protection and sunscreen use.

The rapid increase in melanoma incidence and mortality has given rise to nationwide and international campaigns that encourage the public to protect themselves from solar radiation with clothing, sunscreens, and other measures. The basis of these campaigns has been challenged by proponents of the theory that vitamin D, which is generated in the skin by ultraviolet B radiation, inhibits the development of melanoma. The present investigation tests this theory by examining the relation between dietary vitamin D and melanoma risk in a case-control study. Vitamin D intake was assessed by a food-frequency questionnaire in 165 melanoma patients and 209 controls. After controlling for age, hair color, and family history of melanoma, there was no association of melanoma risk with total vitamin D intake, calorie-adjusted vitamin D intake, vitamin D intake from foods, or consumption of milk or vitamin D supplements. We find no evidence to suggest that vitamin D protects against melanoma, and therefore continue to support the ongoing public health campaigns aimed at reducing sun exposure for the prevention of melanoma.