Lower dialysate calcium (1.25-1.5 mmol/l) may reduce the risk of hypercalcemia, but may lead to negative calcium balance, hyper parathryroidism, and intradialytic hypotension. Increased attention has been paid recently to integrating choice of dialysate calcium level into the understanding of calcium balance, which is determined by diffusive intradialytic fluxes, the dietary calcium content, and the administration of calcium-containing phosphat binders, as well as by dosage of vitamin D analogs. If hypokalemia is coexistent, then critical QTc prolongation may occur.
Higher dialysate calciums level (1.5-1.75 mmol/l) may improve hemodynamic stability during dialysis, but may also increased the risk of hypercalcemia and vascular calcification.
Given that dialysate calcium is only one component in the total calcium balance, dietary calcium, calcium-containing phosphat binders, and the use of vitamin D or its analogs also need to be considered when dialysate calcium is prescribed