Vitamin D deficiency in adults | Health topics A to Z |

vitamin33This is a fact sheet intended for health professionals. For a general overview, see our consumer fact sheet.. Introduction. Vitamin B12 is a water-soluble vitamin that is naturally present inVitamin D is a fat-soluble vitamin that regulates calcium and phosphate homeostasis and is therefore vital for musculoskeletal health. Vitamin D circulates in the blood as both vitamin