Low Plasma 25-Hydroxyvitamin D and Risk of Tobacco-Related Cancer

Abstract

BACKGROUND Tobacco smoke chemicals may influence vitamin D metabolism and function, and conversely vitamin D may modify the carcinogenicity of tobacco smoke chemicals. We tested the hypothesis that lower plasma 25-hydroxyvitamin D [25(OH)D] is associated with a higher risk of tobacco-related cancer in the general population. METHODS A prospective population-based cohort of 9791 individuals from the Copenhagen City Heart Study who were free of cancer at baseline was followed from 1981–1983 until December 2008 with 100% complete follow-up. RESULTS During up to 28 years of follow-up, 1081 participants developed a tobacco-related cancer and 1506 developed other cancers. Decreasing 25(OH)D concentrations, subdivided by clinical categories or by seasonally adjusted percentile categories, were associated with increasing cumulative incidence of tobacco-related cancer (log-rank trend P = 2 × 10−6 and P = 5 × 10−9). Multivariable adjusted hazard ratios of tobacco-related cancer were 1.75 (95% CI, 1.33–2.30) for 25(OH)D <5 vs ≥20 ng/mL, and 2.07 (1.63–2.62) for ≤5th vs >66th percentile. Also, multivariable adjusted hazard ratios for a 50% reduction in 25(OH)D were 1.20 (1.13–1.28) for any tobacco-related cancer, 1.19 (95% CI, 1.09–1.31) for lung cancer, 1.44 (1.19–1.73) for head and neck cancer, 1.28 (1.06–1.54) for bladder cancer, 1.34 (1.04–1.73) for kidney cancer, and 0.95 (0.89–1.01) for other cancers. CONCLUSIONS Lower plasma 25(OH)D was associated with higher risk of tobacco-related cancers, but not with risk of other cancers.