Meta-analysis evaluating vitamin D supplementation in reducing HbA1c and fasting blood sugar in patients with type 2 diabetes`

Abstract

     A lot of previous randomized controlled trials (RCTs) have shown the impact of vitamin D supplementation on reducing HbA1c and fasting blood sugar (FBG) in patients with type 2 diabetes. However, some studies still disagree with that opinion. Therefore, it is necessary to conduct a meta-analysis of qualified RCTs according to the 2010 Consolidated Standards of Reporting Trials (CONSORT 2010) criteria to reach a final conclusion. Documents were collected on 3 databases Pubmed, Cochrane and Embase. The method of this study was inverse variance with the random effect model (RE) and the confidence interval (CI) being 95 %. Finally, 23 tests were taken, in which there are 21 tests on HbA1c and 17 tests on FBG with Mean Difference (MD) = -0.29; 95 % CI: (-0.52)-(-0.06) and MD = 0.07; 95 % CI: (-0.22)-(0.35), respectively. Conclusion: Oral vitamin D supplementation reduces HbA1c levels in type 2 diabetes patients but has no effect on FBG levels.