The case against calcium-based phosphate binders.

Disturbances of mineral metabolism are associated with significant morbidity and mortality in patients with chronic kidney disease. Unfortunately, some of the treatments for these disturbances also have been found to be associated with morbidity. More recently, there is increasing evidence in the form of prospective, randomized trials that the use of calcium-based phosphate binders contributes to progressive coronary artery and aorta calcification compared with the non-calcium-containing binder sevelamer. Moreover, there is compelling biologic plausibility that hyperphosphatemia and excess exogenous calcium administration can accelerate vascular calcification. Unfortunately, there is no bedside test that can determine whether there is a dose of calcium salts (either as maintenance or as cumulative dose) that can be administered safely, and, unfortunately, the serum calcium concentration does not reflect calcium balance. Therefore, calcium-based phosphate binders should be avoided in many, if not most, patients who are undergoing dialysis.