Effectiveness of Vitamin D Supplementation on Biochemical, Clinical, and Inflammatory Parameters in Patients with Different Types of Diabetes: A Systematic Review and Meta-Analysis.

2025-09-18
Nutrients 17(18)
- Alejandro Bruna-Mejías
- Rocío Valdivia-Arroyo
- Emelyn Sofia Becerra-Rodríguez
- Ignacio Clasing-Cárdenas
- Yesica Tatiana Castaño-Gallego
- Guinevere Granite
- Mathias Orellana-Donoso
- Gustavo Oyanedel-Amaro
- Pablo Nova-Baeza
- Gloria Cifuentes-Suazo
- Alejandra Suazo-Santibañez
- Juan Sanchis-Gimeno
- Héctor Gutiérrez Espinoza
- Juan José Valenzuela-Fuenzalida

PubMed: 41010515
DOI: 10.3390/nu17182991

Study Design

Type: Meta-Analysis
Population: patients with diabetes and prediabetes
Methods: A comprehensive search of multiple databases was performed using keywords including "diabetes mellitus," "type 2 diabetes," "vitamin D supplementation," and "VD supplementation." Twenty studies met the inclusion criteria.

Rigorous Journal

Background and Aims: Numerous clinical and observational studies have examined the role of vitamin D in glycemic control and metabolic regulation among diabetic patients, but findings remain inconsistent. This meta-analysis aimed to assess the effects of vitamin D supplementation on glycosylated hemoglobin (HbA1c%), HOMA-IR, HOMA-β, LDL cholesterol, total cholesterol, triglycerides, fasting insulin, fasting plasma glucose, C-reactive protein, and the likelihood of reversion to normoglycemia in prediabetic individuals. Methods: A comprehensive search of multiple databases was performed using keywords including "diabetes mellitus," "type 2 diabetes," "vitamin D supplementation," and "VD supplementation." Twenty studies met the inclusion criteria. Results: Vitamin D supplementation was associated with significant improvements across several parameters, including HOMA-β (SMD = 0.71; 95% CI: 0.63-0.80; p < 0.00001), HDL cholesterol (SMD = 0.07; 95% CI: 0.05-0.09; p < 0.00001), and others (SMD = -0.40; 95% CI: -0.45 to -0.34; p < 0.00001). Conclusions: Vitamin D supplementation appears to provide beneficial effects on glycemic, lipid, and inflammatory markers in patients with diabetes and prediabetes. Specifically, supplementation significantly reduced HbA1c%, HOMA-IR, LDL cholesterol, total cholesterol, triglycerides, fasting insulin, fasting glucose, and C-reactive protein while increasing the rate of normoglycemia among prediabetic individuals. Further research is needed to strengthen the evidence base regarding vitamin D's role in diabetes management.

Research Insights

Vitamin D→Improved Fasting Plasma Glucose
supplementation significantly reduced ... fasting glucose
Effect
Beneficial
Effect size
Small
Vitamin D→Improved Insulin Sensitivity
Vitamin D supplementation was associated with significant improvements across ... HOMA-β (SMD = 0.71; 95% CI: 0.63-0.80; p < 0.00001)
Effect
Beneficial
Effect size
Large
Vitamin D→Increased HDL Cholesterol
HDL cholesterol (SMD = 0.07; 95% CI: 0.05-0.09; p < 0.00001)
Effect
Beneficial
Effect size
Small
Vitamin D→Increased Reversion to Normoglycemia
increasing the rate of normoglycemia among prediabetic individuals
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced Blood Cholesterol
supplementation significantly reduced ... total cholesterol
Effect
Beneficial
Effect size
Small
Vitamin D→Reduced C-Reactive Protein Levels
supplementation significantly reduced ... C-reactive protein
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced Fasting Glucose
supplementation significantly reduced ... fasting glucose
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced Glycosylated Hemoglobin
supplementation significantly reduced HbA1c%
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced HOMA-IR
supplementation significantly reduced ... HOMA-IR
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced HbA1c Level
Vitamin D supplementation was associated with significant improvements across several parameters, including ... significantly reduced HbA1c%
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced Insulin Levels
supplementation significantly reduced ... fasting insulin
Effect
Beneficial
Effect size
Moderate
Vitamin D→Reduced LDL Cholesterol
supplementation significantly reduced ... LDL cholesterol
Effect
Beneficial
Effect size
Small
Vitamin D→Reduced Triglyceride Levels
supplementation significantly reduced ... triglycerides
Effect
Beneficial
Effect size
Small