Are low ultraviolet B and vitamin D associated with higher incidence of multiple myeloma?

Background: The purpose of this study was to determine whether an inverse association exists between latitude, solar ultraviolet B (UVB) irradiance, and incidence rates of multiple myeloma. Methods Associations of latitude and UVB irradiance with age-standardized incidence rates of multiple myeloma were analyzed for 175 countries while controlling for sex-specific obesity prevalence, cigarette consumption, and alcohol consumption using multiple linear regression. Results Incidence rates of multiple myeloma were greater at higher latitudes (R-2 for latitude for males = 0.31, p < 0.0001; females R-2=0.27, p < 0.0001). In regression models for males (R-2=0.62, p < 0.0001) and females (R-2=0.51, p < 0.0001), UVB irradiance was independently inversely associated with incidence rates. Conclusions Age-adjusted incidence rates of multiple myeloma were higher in countries with lower solar UVB irradiance. Further investigation is warranted in individuals of the association of prediagnostic serum 25 (OH)D with risk. (C) 2014 Elsevier Ltd. All rights reserved.