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