Vitamin D valuable supplement for improving glycemic control in diabetes patients

Vitamin D has potential extra skeletal outcomes in diabetes and many other diseases. Some hypotheses state its anti-diabetic properties while it may have an essential role in glucose homeostasis.

The question is, Is there any role of Vitamin D in people with diabetes for glycemic control? The evidence remains conflicting in this context.

Mohammad Ashraf Farahmand and colleagues from Tehran University of Medical Sciences have assessed the role of Vitamin D supplementation in type 2 diabetes (T2D) patients. The indicators of glycemic control were fasting plasma glucose (FPG), HbA1c, and homeostasis model assessment insulin resistance (HOMA-IR).

The researchers collected data from electronic databases like PubMed/Medline, Web of Science, Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and NIH’s Clinical Trials Registry.

The study summary includes the following:

• The study included a meta-analysis having 46 RCTs.
• The RCTs had 2164 intervention subjects and 2149 placebo controls.
• There was a significant change in pooled analyses for HbA1c between the two groups. The weighted mean difference (WMD) was -0.20%.
• After Analysing Fasting Plasma Glucose, a significant reduction was noted in the intervention group with WMD of -5.02 mg/dl after Vitamin D supplementation.
• Pooled analysis results for HOMA-IR revealed a significant change between the two groups with -0.42.
• As shown in subgroup analyses, the most efficacy was in a higher dose, short intervention period and in patients who had a deficiency of vitamin D.

To conclude, Vitamin D supplementation is beneficial for T2D patients because it reduces FPG, HbA1c, and HOMA-IR in patients with deficient vitamin D status.

The researchers added that the effect is prominent when vitamin D is given in large doses and for a short time.

Further reading:

Farahmand, M.A., Daneshzad, E., Fung, T.T. et al. What is the impact of vitamin D supplementation on glycemic control in people with type-2 diabetes: a systematic review and meta-analysis of randomized controlled trials. BMC Endocr Disord 23, 15 (2023). https://doi.org/10.1186/s12902-022-01209-x