Prospective population-based study of the association between serum 25-hydroxyvitamin-D levels and the incidence of specific types of cancer

Background: Observational studies have suggested an inverse association between vitamin D status and cancer. We investigated the prospective associations between vitamin D status and the total and specific type of cancer in three cohorts from the general Danish population. Methods: A total of 12,204 individuals from 18-71 years old were included. The level of 25-hydroxyvitamin D was measured at baseline, and information about cancer was obtained from the Danish Cancer Registry. Results: During the 11.3 year median follow-up time, there were 1,248 incident cancers. Hazard ratios (HR; 95% confidence intervals [CIs]) per 10 nmol/l higher baseline vitamin D level were: for all cancers (HR=1.02, 95% CI: 0.99, 1.04), all cancers excl. non-melanoma skin cancer, NMSC (HR=1.00, 95% CI: 0.97, 1.03), head and neck cancer (HR=0.97, 95% CI: 0.84, 1.12), colorectal cancer (HR=0.95, 95% CI: 0.88, 1.02), cancer of bronchus and lung (HR=0.98, 95% CI: 0.91, 1.05), breast cancer (HR=1.02, 95% CI: 0.96, 1.09), cancer of the uterus (HR=1.10, 95% CI: 0.95, 1.27), prostate cancer (HR=1.00, 95% CI: 0.93, 1.08), cancer of the urinary organs (HR=1.01, 95% CI: 0.90, 1.14), NMSC (HR=1.06, 95% CI: 1.02, 1.10), and malignant melanoma (HR=1.06, 95% CI: 0.95, 1.17). Conclusions: Apart from a significantly higher risk for non-melanoma skin cancer with higher vitamin D status, we found no statistically significant associations between vitamin D status and total or specific cancers. Impact: Our results do not indicate that there is an impact of vitamin D on total cancer incidence.