Vitamin D: More Is Not Better

[image: Vitamin D bottle] Vitamin D is critical for health. Virtually every cell in the body has a vitamin D receptor, which, when bound to vitamin D, can influence the expression of more than 200 genes (1, 2). Vitamin D promotes calcium absorption in the intestine and maintains calcium and phosphate levels in the blood, protecting against osteoporosis, rickets, and bone fracture (3, 4). It also regulates immune function, cell growth, and neuromuscular function ( 5, 6). With the many roles that vitamin D plays in the body, deficiency of this fat-soluble vitamin is a real cause for c... more »