Vitamin D deficiency correlates with an increased risk of developing type-2 diabetes (T2D), according to a study published in Critical Reviews in Food Science and Nutrition.

The study researchers sought to assess the link between vitamin D status and risk of T2D and prediabetes in adults. They conducted a search for all published articles in five electronic databases (MEDLINE/PubMed, EMBASE, Institute for Scientific Information, Scopus and Google scholar). Overall, they included 28 prospective cohort and nested case-control studies and 83 cross-sectional and case-control studies for analysis.

The results of the prospective studies showed that high versus low levels of vitamin D were associated with a significantly reduced risk of T2D, combined T2D, and pre-diabetes (35%, 30% and 51%, respectively). In the cross-sectional and case-control studies, the researchers observed that the highest versus lowest levels of serum vitamin D were linked to reduced odds of T2D (OR=0.64; 95% CI, 0.57-0.72) and combined T2D and pre-diabetes (OR=0.79; 95% CI, 0.74-0.85); but not pre-diabetes (OR=0.64; 95%CI, 0.17-2.37).

“This meta-analysis of epidemiologic studies disclosed that serum vitamin D level was reversely associated with the risk of T2D and combined T2D and prediabetes in adults, in a dose-response manner,” the researchers concluded. They added that the association “was not remarkable for pre-diabetes.”

Keywords:  Serum 25-hydroxy vitamin D, epidemiologic studies, meta-analysis, prediabetes, type 2 diabetes