Skip to main content
Evidence-Based Supplement Research
Evidence-Based Supplement Research
Pillser
Search
Sign UpLog In

Vitamin D and Reduced Fasting Blood Glucose Levels

Research synthesisLow evidenceSmall effect3 studies · 1 beneficial · 2 neutral · 0 harmful

Across 3 studies on vitamin D for reducing fasting blood glucose, 1 reported a beneficial small effect and 2 reported neutral effects. The sole significant finding came from a meta-analysis in patients with MAFLD (effect size: -0.21 mmol/L, 95% CI: -0.41 to -0.02). Median study duration was 84 days, but conclusions should be considered preliminary given the small evidence base.

  • Studied populations: patients with MAFLD; patients with type 2 diabetes and low vitamin D levels

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. The beneficial result was observed specifically in MAFLD patients, while neutral results came from broader or T2DM populations, suggesting potential population-dependent effects.

Generated May 13, 2026
Doses used in studies
  • IU/day: 10,000 (median 10,000, IQR 10,000–10,000) — 1 study
Time to effect
Median: 2.8 months · IQR 2.8 months–2.8 months · Range 2.8 months–2.8 months — Reported in 1 of 3 studies
Safety in these studies
3 of 3 papers
Back to top