Function & Metabolism

  • 1,25-Dihyroxycholecalciefrol (Calcitriol) binds to Vitamin D Binding Protein in blood to be transported to the target organs
  • In target organs and cells , Calcitriol acts by binding to Vitamin D Receptor (VDR)
  • VDR is the key receptor for the function of Vitamin D
  • VDRs are widespread in nucleus (control center of the cell) of many tissues like immune system cells or epidermal cells in the skin (keratinocytes)
  • Irrespective of bone metabolism, Calcitriol regulates several hundred genes via VDRs , some researchers think it could be as much as 5% of the entire human genome

(4.12.13)