Effects of Vitamin D Supplementation on Prevention of Type 2 Diabetes in Patients With Prediabetes: A Systematic Review and Meta-analysis

source extracted confidence: high 2026-04-09
#adolescent #adult #aged #aged-80-and-over #controlled-clinical-trials-as-topic

Effects of Vitamin D Supplementation on Prevention of Type 2 Diabetes in Patients With Prediabetes: A Systematic Review and Meta-analysis

Zhang et al., 2020 | Diabetes Care | Meta Analysis

Citation

Zhang Yu, Tan Huiwen, ... Fang Fang. Effects of Vitamin D Supplementation on Prevention of Type 2 Diabetes in Patients With Prediabetes: A Systematic Review and Meta-analysis. Diabetes Care. 2020-Jul;43(7):1650-1658. doi:10.2337/dc19-1708

Abstract

BACKGROUND: While observational studies have shown an association between vitamin D insufficiency and diabetes, it is unclear whether intervention with vitamin D supplements can lower the risk of type 2 diabetes mellitus (T2DM). PURPOSE: To assess whether vitamin D supplementation reduces the risk of T2DM in people with prediabetes. DATA SOURCES: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) from inception to 5 July 2019. STUDY SELECTION: We included randomized controlled trials assessing vitamin D supplementation versus placebo in relation to new-onset T2DM in people with prediabetes. DATA EXTRACTION: We screened studies and extracted data from published trials independently. DATA SYNTHESIS: We identified eight eligible trials with a total of 4,896 subjects. Vitamin D supplementation significantly reduced the risk of T2DM (risk ratio [RR] 0.89 [95% CI 0.80-0.99]; I 2 = 0%). Benefit was found in nonobese subjects (RR 0.73 [95% CI 0.57-0.92]) but not in obese subjects (RR 0.95 [95% CI 0.84-1.08]) (P interaction = 0.048). The reversion of prediabetes to normoglycemia occurred in 116 of 548 (21.2%) participants in the vitamin D group and 75 of 532 (14.1%) in the control group. Vitamin D supplementation increased reversion rate of prediabetes to normoglycemia (RR 1.48 [95% CI 1.14-1.92]; I 2 = 0%.) LIMITATIONS: Definitions of prediabetes and new-onset diabetes in eligible studies were different, and long-term data on outcomes of T2DM prevention were lacking. CONCLUSIONS: In persons with prediabetes, vitamin D supplementation reduces the risk of T2DM and increases the reversion rate of prediabetes to normoglycemia. The benefit of the prevention of T2DM could be limited to nonobese subjects. Individual participant data meta-analyses are needed to confirm these findings.

Key Findings

In persons with prediabetes, vitamin D supplementation reduces the risk of T2DM and increases the reversion rate of prediabetes to normoglycemia. The benefit of the prevention of T2DM could be limited to nonobese subjects. Individual participant data meta-analyses are needed to confirm these findings.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 0
Age Range See abstract
Condition diabetes

MeSH Terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Controlled Clinical Trials as Topic
  • Diabetes Mellitus, Type 2
  • Dietary Supplements
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prediabetic State
  • Vitamin D
  • Young Adult

Evidence Classification

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

Provenance

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