renal physiology (calcium)

Last reviewed 01/2018

The kidneys are the main route of calcium excretion. Renal handling of calcium is dependent upon several factors:

  • concentration of calcium in glomerular filtrate, itself dependent upon ionized calcium levels of plasma
  • glomerular filtration rate
  • reabsorption of calcium:
    • normally, in excess of 95% of filtered calcium is reabsorbed
    • reabsorption is dependent upon parathyroid hormone which acts on the proximal and distal renal tubules to increase calcium reabsorption but decrease phosphate reabsorption