A recent randomized clinical trial in Canada among 96 individuals with vitamin D insufficiency [mean 25(OH)D = 51.1 nmol/L at baseline] and at high risk of diabetes or with newly diagnosed type 2 diabetes found that vitamin D3 supplementation (5000 IU daily) for 6 months significantly increased peripheral insulin sensitivity and β-cell function [9]. This evidence concerns the gene INS and type 2 diabetes mellitus.