Calcium has a vital role to play in the effective working of the majority of cells in the body and it is therefore important that the optimal level be maintained by the body. A reduction in serum calcium can stimulate parathyroid hormone (PTH) release which may then increase bone resorption, increase renal calcium reabsorption, and stimulate renal conversion of 25-hydroxyvitamin D3, to the active 1,25-dihydroxyvitamin D3, which then will increase intestinal calcium absorption. These mechanisms restore the serum calcium to normal and inhibit further production of PTH and 1,25-dihydroxyvitamin D3.1
This is a companion discussion topic for the original article at https://patient.info/doctor/hypercalcaemia