Evaluating the Use of Vitamin D Supplementation to Improve Glycaemic Outcome in Type 2 Diabetes Mellitus Patients: A Systematic Review of Evidence

Abstract

Background: The evidence indicates that vitamin D [25(OH)D] improves glycaemic outcomes in type 2 Diabetes mellitus patients. The outcome measures used to determine the accuracy of this hypothesis are: glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG) and homeostasis model assessment-insulin resistance (HOMA-IR). Methods: We performed a systematic review and meta-analysis which included all previous randomised controlled trial (RCT) studies that assessed the effects of vitamin D on glucose metabolism. We carried out an extensive electronic database search of published and unpublished RCTs, evaluating the association between vitamin D and glycaemic outcomes in type 2 diabetes mellitus patients. We clusion, although vitamin D has been extensively studied in relation to some glycaemic outcomes and some indications that increased plasma vitamin D concentrations might be linked to prevention of T2DM, firm universal conclusions about its benefits cannot be drawn. Further studies with better designed trials and larger sample sizes are needed to draw firmer conclusions.