Role of calcium supplementation in patients with mild renal failure

A low-protein diet has been shown to be effective in the prevention of progression of renal failure. However, the role of protein and that of phosphate intake have not been definitely separated. To determine the use of calcium (CaCO3) as a phosphate binder and a possible hypotensive agent, we performed a prospective, double-blind study of oral calcium in patients with mild-to-moderate renal failure (SCr less than 5.0 mg/dl). Thirty-six patients (20 m, 16 f) were studied. After a 2-month control period, either CaCO3 (6 g/day, 12 Cap) or placebo was given for 3 months. There was no significant difference in BUN, S-Sr, S-Ca, S-Pi, 24-hour Ccr, and blood pressure during the study period both in the genuine and the placebo group. Urine phosphate was decreased by about 50% in the CaCO3 group. Calcium carbonate is feasible as a phosphate binder for patients with mild-to-moderate renal failure.