Of great interest for our present focus, hypovitaminosis D has been reported to impair islet insulin secretion and to increase peripheral insulin resistance, two major risk factors for progression to T2DM; furthermore, hypovitaminosis D is predictive of abnormalities in most of the variables monitored in patients with metabolic syndromes, including T2DM itself [22,23]. The gene discussed is INS; the disease is rickets.