Impact of vitamin D supplementation on glycaemic control in gestational diabetes

Takeaway

• This meta-analysis suggests that vitamin D supplementation has the potential to promote glycaemic control in women with gestational diabetes mellitus (GDM).
• Vitamin D supplementation has a significant effect on serum insulin, fasting blood glucose and glycated haemoglobin.
• However, findings should be interpreted with caution because of limited number of studies in the meta-analysis.

Why this matters

• The prevalence of vitamin D deficiency is high during pregnancy and is associated with various complications, including GDM.
• However, there is no consensus regarding the effect of vitamin D supplementation in improving adverse effects in GDM.

Study design

• 5 randomised controlled trials involving 173 participants supplemented with vitamin D and 153 control participants met eligibility criteria after a search on Embase and PubMed.
• Funding: University of Greenwich.

Key result

• Vitamin D supplementation during pregnancy was associated with reduction in:
  • fasting blood glucose by a mean of 0.46 mmol/L (95% CI, −0.68 to −0.25; P<.001; I², 41%),
  • glycated haemoglobin by a mean of 0.37% (95% CI, −0.65 to −0.08; P<.01) and
  • serum insulin concentration by a mean of 4.10 µIU/mL (95% CI, −5.50 to −2.71; P<.001; I², 0%).

Limitations

• Limited number of studies.