Efficacy of vitamin D supplementation on glycaemic control in type 2 diabetes: An updated systematic review and meta-analysis of randomized controlled trials

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#humans #blood-glucose #diabetes-mellitus-type-2 #dietary-supplements #glycated-hemoglobin

Efficacy of vitamin D supplementation on glycaemic control in type 2 diabetes: An updated systematic review and meta-analysis of randomized controlled trials

Chen et al., 2024 | Diabetes Obes Metab | Meta Analysis

Citation

Chen Wei, Liu Lili, Hu Fang. Efficacy of vitamin D supplementation on glycaemic control in type 2 diabetes: An updated systematic review and meta-analysis of randomized controlled trials. Diabetes Obes Metab. 2024-Dec;26(12):5713-5726. doi:10.1111/dom.15941

Abstract

AIM: To assess the effects of vitamin D interventions on glycaemic control in subjects with type 2 diabetes (T2D). METHODS: We searched PubMed, EMBASE, Web of Science and the Cochrane Library for relevant studies. Serum 25(OH)D, fasting blood glucose (FBG), HbA1c, fasting insulin and Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) were analysed. RESULTS: We identified 39 randomized controlled trials involving 2982 subjects. Results showed a significant decline in the vitamin D group, as shown by the FBG weighted mean difference (WMD; -0.49 [95% confidence interval {CI}: -0.69 to -0.28] mmol/L), HbA1c (WMD -0.30% [95% CI: -0.43 to -0.18]), HOMA-IR (WMD -0.39 [95% CI -0.64 to -0.14]) and insulin (WMD -1.31 [95% CI: -2.06 to -0.56] μIU/mL). Subgroup analyses indicated that the effects of vitamin D supplementation on glycaemic control depend on the dosage and duration of supplementation, baseline 25(OH)D levels and the body mass index of patients with T2D. CONCLUSIONS: Vitamin D supplementation can significantly reduce serum FBG, HbA1c, HOMA-IR and fasting insulin levels in T2D patients; the effects were especially prominent when vitamin D was given in a short-term, high dosage to patients with a vitamin D deficiency, who were overweight, or had an HbA1c of 8% or higher at baseline. Our study suggests that vitamin D supplements can be recommended as complementary treatment for T2D patients.

Key Findings

We identified 39 randomized controlled trials involving 2982 subjects. Results showed a significant decline in the vitamin D group, as shown by the FBG weighted mean difference (WMD; -0.49 [95% confidence interval {CI}: -0.69 to -0.28] mmol/L), HbA1c (WMD -0.30% [95% CI: -0.43 to -0.18]), HOMA-IR (WMD -0.39 [95% CI -0.64 to -0.14]) and insulin (WMD -1.31 [95% CI: -2.06 to -0.56] μIU/mL). Subgroup analyses indicated that the effects of vitamin D supplementation on glycaemic control depend on the

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population type 2 diabetes
Sample Size 2982
Age Range See abstract
Condition diabetes

MeSH Terms

  • Humans
  • Blood Glucose
  • Diabetes Mellitus, Type 2
  • Dietary Supplements
  • Glycated Hemoglobin
  • Glycemic Control
  • Insulin
  • Insulin Resistance
  • Randomized Controlled Trials as Topic
  • Treatment Outcome
  • Vitamin D
  • Vitamin D Deficiency

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Systematic Review, Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't
  • Vertical: vitamin-d-diabetes

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09