INS and diabetes mellitus: In line with a causative role for iron in diabetic disease, dietary iron restriction has been reported to improve beta-cell function and glucose tolerance in ob/ob mice (84,144), and phlebotomy has been shown to improve insulin sensitivity, insulin secretion and glucose regulation in type 2 diabetes mellitus (T2DM) [152,153] even if clinical data, collected so far on iron depletion strategy, still appear inconclusive [154,155].