Dietary vitamin D intake and risk of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition: The EPIC-InterAct study
Abbas S., Linseisen J., Rohrmann S., Beulens JWJ., Buijsse B., Amiano P., Ardanaz E., Balkau B., Boeing H., Clavel-Chapelon F., Fagherazzi G., Franks PW., Gavrila D., Grioni S., Kaaks R., Key TJ., Khaw KT., Kühn T., Mattiello A., Molina-Montes E., Nilsson PM., Overvad K., Quirós JR., Rolandsson O., Sacerdote C., Saieva C., Slimani N., Sluijs I., Spijkerman AMW., Tjonneland A., Tumino R., Van Der A DL., Zamora-Ros R., Sharp SJ., Langenberg C., Forouhi NG., Riboli E., Wareham NJ.
Background/Objectives: Prospective cohort studies have indicated that serum vitamin D levels are inversely related to risk of type 2 diabetes. However, such studies cannot determine the source of vitamin D. Therefore, we examined the association of dietary vitamin D intake with incident type 2 diabetes within the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct study in a heterogeneous European population including eight countries with large geographical variation. Subjects/Methods: Using a case-cohort design, 11 245 incident cases of type 2 diabetes and a representative subcohort (N=15 798) were included in the analyses. Hazard ratios (HR) and 95% confidence intervals (CIs) for type 2 diabetes were calculated using a Prentice-weighted Cox regression adjusted for potential confounders. Twenty-four-hour diet-recall data from a subsample (N=2347) were used to calibrate habitual intake data derived from dietary questionnaires. Results: Median follow-up time was 10.8 years. Dietary vitamin D intake was not significantly associated with the risk of type 2 diabetes. HR and 95% CIs for the highest compared to the lowest quintile of uncalibrated vitamin D intake was 1.09 (0.97-1.22) (P trend =0.17). No associations were observed in a sex-specific analysis. The overall pooled effect (HR (95% CI)) using the continuous calibrated variable was 1.00 (0.97-1.03) per increase of 1 μg/day dietary vitamin D. Conclusions: This observational study does not support an association between higher dietary vitamin D intake and type 2 diabetes incidence. This result has to be interpreted in light of the limited contribution of dietary vitamin D on the overall vitamin D status of a person.