Vitamin D and pancreatic cancer : a pooled analysis from the Pancreatic Cancer Case-Control Consortium

Background: The potential role of vitamin D in the aetiology of pancreatic cancer is unclear, with recent studies suggesting both positive and negative associations. Patients and methods: We used data from nine case-control studies from the International Pancreatic Cancer Case- Control Consortium (PanC4) to examine associations between pancreatic cancer risk and dietary vitamin D intake. Study-specific odds ratios (ORs) were estimated using multivariable logistic regression, and ORs were then pooled using a random-effects model. From a subset of four studies, we also calculated pooled estimates of association for supplementary and total vitamin D intake. Results: Risk of pancreatic cancer increased with dietary intake of vitamin D [per 100 international units (IU)/day: OR = 1.13, 95% confidence interval (CI) 1.07-1.19, P = 7.4 × 10-6, P-heterogeneity = 0.52; ≥230 versus <110 IU/day: OR = 1.31, 95% CI 1.10-1.55, P = 2.4 × 10-3, P-heterogeneity = 0.81], with the association possibly stronger in people with low retinol/vitamin A intake. Conclusion: Increased risk of pancreatic cancer was observed with higher levels of dietary vitamin D intake. Additional studies are required to determine whether or not our finding has a causal basis.