title: Plasma 25-hydroxyvitamin D and risk of non-melanoma and melanoma skin cancer: a prospective cohort study.
abstract: Sun exposure is a major risk factor for skin cancer and is also an important source of vitamin D. We tested the hypothesis that elevated plasma 25-hydroxyvitamin D (25-OH-vitD) associates with increased risk of non-melanoma and melanoma skin cancer in the general population. We measured plasma 25-OH-vitD in 10,060 white individuals from the Danish general population. During 28 years of follow-up, 590 individuals developed non-melanoma skin cancer and 78 developed melanoma skin cancer. Increasing 25-OH-vitD levels, by clinical categories or by seasonally adjusted tertiles, were associated with increasing cumulative incidence of non-melanoma skin cancer (trend P=2 × 10(-15) and P=3 × 10(-17)) and melanoma skin cancer (P=0.003 and P=0.001). Multivariable adjusted hazard ratios of non-melanoma skin cancer were 5.04 (95% confidence interval (CI): 2.78-9.16) for 25-OH-vitD ≥50 vs. <25 nmol  l(-1), and 4.02 (2.45-6.60) for top versus bottom tertile. Multivariable adjusted hazard ratios of melanoma skin cancer were 4.7 (0.96-23.3) for 25-OH-vitD ≥50 vs. <25 nmol  l(-1), and 6.3 (1.38-28.8) for top versus bottom tertile. The absolute 20-year risk was 11% for non-melanoma skin cancer and 1.5% for melanoma skin cancer, in participants with age >60 years, 25-OH-vitD winter levels ≥50 nmol  l(-1), and performing outdoor exercise. In conclusion, we show that increasing levels of 25-OH-vitD are associated with increased risk of non-melanoma and melanoma skin cancer.
authors.affiliation: Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark.
authors.forename: Shoaib
authors.initials: S
authors.lastname: Afzal
authors.affiliation: Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark; The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Børge G
authors.initials: BG
authors.lastname: Nordestgaard
authors.affiliation: Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark; The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address: Stig.Egil.Bojesen@regionh.dk.
authors.forename: Stig E
authors.initials: SE
authors.lastname: Bojesen
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008545:Melanoma / Q000097:blood / Q000453:epidemiology*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012621:Seasons; D012878:Skin Neoplasms / Q000097:blood / Q000453:epidemiology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014408:Biomarkers, Tumor; D014807:Vitamin D; C104450:25-hydroxyvitamin D