INS and type 2 diabetes mellitus: Our findings are consistent with results of many other published studies, in which the insulin resistance appears to be decreased in T2DM patients who had received vitamin D. For example,Inzucchi showed a 60% improvement in insulin sensitivity by increased serum 25 (OH)D concentration from 10 to 30 ng/ml(25 to75nmol/l), by which metformin or troglitazone were 54% and 13% respectively [14].