Vitamin D supplements in Prediabetes patients reduce type 2 diabetes risk, says study
USA: Vitamin D supplementation in patients with prediabetes significantly reduces the risk of type 2 diabetes (T2D), suggests a recent study published in the Journal of Clinical Endocrinology & Metabolism
The effect of vitamin D supplementation on T2D risk remains controversial. Most randomized controlled trials (RCTs) have been small or have reported low doses of vitamin D.
Mahmoud Barbarawi, Department of Internal Medicine, Hurley Medical Center/Michigan State University, Flint, MI, USA, and colleagues conducted a meta-analysis of RCTs testing vitamin D supplementation in the prevention of T2D.
The researchers performed a database search of PubMed/MEDLINE, EMBASE, and the Cochrane Library from inception through September 15, 2019. RCTs that reported the effect of vitamin D supplementation for at least 1 year on T2D prevention, were included.
Two independent reviewers extracted the data. The risk ratios (RRs) and 95% confidence intervals (CIs) were reported. The primary outcome of the meta-analysis was the incidence of T2D.
A total of nine RCTs with 43 559 participants, were included. The mean age (standard deviation) was 63.5 (6.7) years.
Key findings of the study include:
- The RR for vitamin D compared with placebo was 0.96.
- In trials testing moderate to high doses of supplementation (≥1000 IU/day), all conducted among participants with prediabetes, the RR for vitamin D compared with placebo was 0.88.
- The trials testing lower doses, which were conducted in general population samples, showed no risk reduction (RR, 1.02).
"In patients with prediabetes, vitamin D supplementation at moderate to high doses (≥1000 IU/day), significantly reduced the incidence risk of T2DM, compared with placebo," concluded the authors.
The study, "Effect of Vitamin D Supplementation on the Incidence of Diabetes Mellitus," is published in the Journal of Clinical Endocrinology & Metabolism.