Predicted plasma 25‐hydroxyvitamin D and risk of renal cell cancer

Abstract

BackgroundAlthough the kidney is a primary organ for vitamin D metabolism, the association between vitamin D and renal cell cancer (RCC) remains unclear.MethodsWe prospectively evaluated the association between predicted plasma 25‐hydroxyvitamin D [25(OH)D] and RCC risk among 72,051 women and 46,380 men from 1986 to 2008. Predicted plasma 25(OH)D scores were computed using validated regression models that included major determinants of vitamin D status (race, UV‐B flux, physical activity, body mass index, vitamin D intake, alcohol consumption, and post‐menopausal hormone use in women). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. All statistical tests were two‐sided.ResultsDuring 22 years of follow‐up, we documented 201 cases of incident RCC in women and 207 cases in men. The multivariable HRs between extreme quintiles of predicted 25(OH)D score were 0.51 (95% CI 0.32–0.80) in women, 0.59 (95% CI 0.37–0.94) in men, and 0.55 (95% CI 0.39–0.76; Ptrend < .0001) in the pooled cohorts. An increment of 10 ng/ml in predicted 25(OH)D score was associated with a 43% lower incidence of RCC (pooled HR 0.57; 95% CI 0.43–0.77). We found no significant association between vitamin D intake and RCC incidence.ConclusionHigher predicted plasma 25(OH)D levels were associated with a significantly lower risk of RCC in men and women.