Effect of Vitamin D Supplementation on Improving Glucose Homeostasis in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis
Zhang Y, Tan H, Tang J, Li J, Chong W, Hai Y, Feng Y, Lunsford LD, Xu P, Jia D, Fang F
Published in Frontiers in Endocrinology
Abstract
Meta-analysis of 18 RCTs showing vitamin D supplementation significantly improves fasting glucose and HbA1c in type 2 diabetes patients, particularly those with deficiency. Optimal dose appears to be 4000 IU daily or 50,000 IU weekly.
Methodology
Systematic review and meta-analysis of randomized controlled trials with subgroup and dose analyses.
Key Findings
Pooled randomized trial data show vitamin D supplementation modestly improves fasting glucose, HbA1c and insulin resistance (HOMA-IR) in people with type 2 diabetes, with the clearest effects in participants who were vitamin D deficient at baseline and with higher-dose or shorter-interval regimens.
Conclusions
Vitamin D produces small improvements in glycaemic markers in type 2 diabetes, mainly in deficient patients; it is an adjunct rather than a glucose-lowering therapy.
Limitations
Substantial heterogeneity in dose, dosing interval, duration and baseline vitamin D status; effect sizes are small and of uncertain clinical importance, and surrogate endpoints only.
Supplements Studied
Pooled randomized trial data show vitamin D supplementation modestly improves fasting glucose, HbA1c and insulin resistance (HOMA-IR) in people with type 2 diabetes, with the clearest effects in participants who were vitamin D deficient at baseline and with higher-dose or shorter-interval regimens.
Related Health Concerns
Study Details
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Disclosures
Funding
Institutional / national grant funding in China; no supplement industry sponsorship reported.
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.