Vitamin D deficiency tied to type 2 diabetes and prediabetes in new meta-analysis
Isfahan, Iran: Higher the levels of serum vitamin D lower is the risk of type 2 diabetes (T2D) and combined T2D and prediabetes in adults, according to results from a meta-analysis published in the Critical Reviews in Food Science and Nutrition.
In other words, serum vitamin D levels are inversely related to the risk of T2D and combined T2D and prediabetes. However, the association was not found to be remarkable for prediabetes.
Previous observational studies that investigated the relationship between vitamin D deficiency and abnormal glucose hemostasis have yielded contradictory results. To clarify the same, Parvane Saneei, Isfahan University of Medical Sciences, Isfahan, Iran, and colleagues aimed to evaluate the association of vitamin D status and risk of T2D and prediabetes in adults by conducting a meta-analysis of epidemiologic studies.
Findings of observational studies that investigated the relationship between vitamin D deficiency and abnormal glucose homeostasis were contradictory. This meta-analysis of epidemiologic studies evaluated the association of vitamin D status and risk of type-2 diabetes and prediabetes in adults.
The researchers conducted a systematic search on all published articles in five electronic databases up to August 2020. A total of twenty-eight prospective cohort and nested case-control studies and 83 cross-sectional and case-control investigations were included in the analysis.
Key findings of the study include:
- In prospective studies, high versus low level of vitamin D was respectively associated with significant 35%, 30% and 51% decrease in risk of T2D (RR:0.65), combined T2D and pre-diabetes (RR:0.70) and pre-diabetes (RR:0.49).
- These inverse associations were significant in almost all subgroups.
- Dose–response analysis in prospective studies showed that each 10 ng/ml increase in serum vitamin D levels resulted in 12% and 11% reduced risk of T2D (RR:0.88) and combined T2D and prediabetes (RR:0.89), respectively.
- In cross-sectional and case-control studies, highest versus lowest level of serum vitamin D was linked to reduced odds of T2D (OR:0.64) and combined T2D and pre-diabetes (OR:0.79); but not pre-diabetes (OR:0.64).
"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. However, the association was not remarkable for pre-diabetes," wrote the authors.
The study titled, "Serum vitamin D levels in relation to type-2 diabetes and prediabetes in adults: a systematic review and dose–response meta-analysis of epidemiologic studies," is published in the Critical Reviews in Food Science and Nutrition.