It enhances insulin secretion via calcium-dependent endopeptidases, modulates the PI3K/AKT signaling pathway, interacts with vitamin D receptor (VDR) and vitamin D-binding protein (DBP) gene variations, and reduces inflammation and secondary hyperparathyroidism, which are the key contributors to type 2 diabetes progression [39,40,41]. Here, VDR is linked to secondary hyperparathyroidism.