Format

Send to

Choose Destination
Metabolism. 2017 Aug;73:67-76. doi: 10.1016/j.metabol.2017.05.006. Epub 2017 May 22.

Vitamin D supplementation and glycemic control in type 2 diabetes patients: A systematic review and meta-analysis.

Author information

1
Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, China.
2
Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, China. Electronic address: li-ling76@hotmail.com.

Abstract

INTRODUCTION:

Low vitamin D status has been found to be associated with impaired glycemic control in patients who suffer from type 2 diabetes; however, whether vitamin D supplementation is associated with improved glycemic status remains controversial. The aim of this study was to summarize evidence from randomized controlled trials (RCTs) to assess the efficacy of vitamin D supplementation in reducing glycosylated haemoglobinA1c (HbA1c) and fasting blood glucose (FBG) levels.

MATERIALS/METHODS:

We searched PubMed, Web of Science and the Cochrane Library for reports published up to March 2017. We selected parallel RCTs investigating the effect of vitamin D or vitamin D analogues on HbA1c or FBG levels in type 2 diabetes patients. Cohen's d was calculated to represent the standardized mean difference (SMD) for each study, and the SMDs with 95%confidence intervals (CIs) were pooled using a random effects model.

RESULTS:

Twenty-four studies were included that evaluated HbA1c levels and 18 studies were included that evaluated FBG levels. Meta-analyses showed that vitamin D supplementation was associated with reduced HbA1c levels (standardized mean difference (SMD) -0.25 [-0.45 to -0.05]) but had no influence on FBG levels (SMD -0.14 [-0.31 to 0.03]). However, the subgroup analyses suggested that vitamin D supplementation was associated with reduced HbA1c levels (SMD -0.39 [-0.67 to -0.10]) and FBG (SMD -0.27 [-0.46 to -0.07]) among patients with 25-hydroxyvitamin D (25(OH) D) deficiency at baseline. Significantly reduced HbA1c levels were also observed in association with vitamin D supplementation in the subgroup including type 2 diabetes patients with a body mass index (BMI) <30kg m-2 (SMD -0.30 [-0.54 to -0.07]).

CONCLUSIONS:

Vitamin D supplementation could be effective at improving glycemic control in vitamin D deficient or non-obese type 2 diabetes patients.

KEYWORDS:

Body mass index; Fasting blood glucose; Glycosylated hemoglobinA1c; Vitamin D

PMID:
28732572
DOI:
10.1016/j.metabol.2017.05.006
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center