Abstract: Vitamin D is suggested to have protective effects against type 1 diabetes. However, the results from observational studies have been inconsistent. We aimed to examine their association by conducting a meta-analysis of observational studies. Multiple databases were searched in June 2013 to identify relevant studies including both case-control and cohort studies. Either a fixed- or random-effects model was used to calculate the pooled risk estimate. We identified eight studies (two cohort studies and six case-control studies) on vitamin D intake during early life and three studies (two cohort studies and one case-control study) on maternal vitamin D intake during pregnancy. The pooled odds ratio for type 1 diabetes comparing vitamin D supplementation with non-supplementation during early life was 0.71 (95% confidence interval [CI], 0.51–0.98). Similar results were observed in the case-control subgroup analysis but not in the cohort subgroup analysis. The pooled odds ratio with maternal intake of vitamin D during pregnancy was 0.95 (95% CI, 0.66–1.36). In conclusion, vitamin D intake during early life may be associated with a reduced risk of type 1 diabetes. However, there was not enough evidence for an association between maternal intake of vitamin D and risk of type 1 diabetes in the offspring.
Keywords: vitamin D; type 1 diabetes; early life; pregnancy; meta-analysis
This is an open access article distributed under the
Creative Commons Attribution License which permits unrestricted use, distribution,
and reproduction in any medium, provided the original work is properly cited.
Export to BibTeX
MDPI and ACS Style
Dong, J.-Y.; Zhang, W.; Chen, J.J.; Zhang, Z.-L.; Han, S.-F.; Qin, L.-Q. Vitamin D Intake and Risk of Type 1 Diabetes: A Meta-Analysis of Observational Studies. Nutrients 2013, 5, 3551-3562.
Dong J-Y, Zhang W, Chen JJ, Zhang Z-L, Han S-F, Qin L-Q. Vitamin D Intake and Risk of Type 1 Diabetes: A Meta-Analysis of Observational Studies. Nutrients. 2013; 5(9):3551-3562.
Dong, Jia-Yi; Zhang, Weiguo; Chen, Jiong J.; Zhang, Zeng-Li; Han, Shu-Fen; Qin, Li-Qiang. 2013. "Vitamin D Intake and Risk of Type 1 Diabetes: A Meta-Analysis of Observational Studies." Nutrients 5, no. 9: 3551-3562.