VDR and the 1-α-hydroxylase enzyme are expressed in pancreatic β-cells, and it has been reported that 1,25(OH)2D may have a role in the regulation of insulin production and secretion [52]; in particular, it has been demonstrated that 1,25(OH)2D acts on pancreatic islets stressed by inflammation and vitamin D deficiency [53]. The gene discussed is VDR; the disease is vitamin D deficiency.