Calcium supplementation in chronic kidney disease

Introduction: There is high prevalence of calcium supplementation in the general population and some recent data suggest that this may increase the risk of vascular calcification. Calcium-based binders have been a standard treatment for hyperphosphatemia in patients with chronic kidney disease (CKD). Though as effective as phosphate binders, they provide a source of substantial calcium intake. Areas covered: In addition to the balance studies recently completed to assess the implications of calcium loading in CKD, we also review observational studies and clinical trials involving calcium-based binders. Clinically significant endpoints such as vascular calcification, mortality and bone morphology were evaluated. The existing data are concerning for the role of calcium supplementation and calcium binder use in patients with renal compromise. Expert opinion: There are few guidelines on advised calcium intake in patients with renal failure; however, on the basis of existing data, it may be safer to have the upper limit of calcium intake (including that of supplementation/binder use) up to 1 g. The old Kidney Disease Outcomes Quality Initiative suggestion of limiting the calcium intake to 2 g may need to be reconsidered.