The association between dialysate calcium (DCa) concentration and mortality in hemodialysis (HD) patients is controversial. Studies have shown that complications of hypercalcemia and hyperparathyroidism can exacerbate the progression of cardiovascular disorders (CVDs) and mineral bone disease (MBD) in patients receiving maintenance hemodialysis (MHD).

Hence, the role of dialysate calcium concentration is of utmost importance in such patient population. Although KDIGO recommends the use of Ca dialysates of concentration of 1.25-1.5 mmol for MHD, the optimal concentration still remains controversial. A recent meta-analysis revealed that low calcium concentration dialysate (LCD-1.25 mmol) was effective in lowering serum Ca levels in patients receiving long-term MHD therapy. Similarly, the use of LCD has been found to be safe and efficacious even in elderly patients (>65 years) undergoing MHD. Also, in comparison to high Ca dialysate concentration (1.5 or 1.75 mmol), LCD was found to be more beneficial in lowering arterial calcifications and delaying the progression of atherosclerosis. Higher serum calcium levels have been associated with an increased risk of developing coronary artery disease, and Indians have a genetic predisposition to higher calcium levels. Hence, low concentration calcium bath could be a beneficial strategy in Indian HD patients.

However, in-spite of all the benefits of LCD strategy, it has failed to demonstrate any significant mortality benefit over high calcium dialysate (HCD). Also, studies have shown that long-term use of LCD <1.25 mmol leads to higher episodes of intradialytic hypotension and congestive heart failure. Widespread use of either LCD or HCD should not be adopted as a singular strategy, rather the HD prescription should be individualized as far as possible until the verdict is out/more robust data is available on the optimal dialysate calcium concentration.