Vitamin D & Bone Metabolism

  • Vitamin D's primary function is serum calcium and phosphate metabolism and, in turn, the maintenance of bone health
  • Vitamin D increases the absorption of calcium and phosphate from the intestine
  • Additional absorption of calcium from the kidneys with the help of parathyroid hormone is also facilitated by Vitamin D
  • Without Vitamin D, only 10-15% of dietary calcium and  60% of phosphate can be absorbed
  • If vitamin D falls below critical levels, parathyroid hormone increases
  • Parathyroid hormone mobilises calcium from bone and increases the absorption of calcium from the kidneys
  • Traditionally, Vitamin D deficiency level is decided according to the values at which parathyroid hormone levels start to increase

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