Abstract
Vitamin D deficiency may have an important role in the development of Type-2 diabetes(Reference Pittas, Dawson-Hughes, Sheehan, Ware, Knowler and Aroda1,Reference Kayaniyil, Vieth, Retnakaran, Knight, Qi and Gerstein2) . Low vitamin D concentration has broad-ranging effects that are both directly (by activation of the vitamin D receptor) and indirectly (by modulation of intracellular calcium concentration) related to impaired pancreatic β-cell function and insulin resistance(Reference Norman, Frankel, Heldt and Grodsky3). The purpose of this systematic review and meta-analysis was to examine the effect of vitamin D supplementation on insulin resistance and glycaemic control in participants with prediabetes.