Belmar (Sevelemer Carbonate) is used to lower high blood phosphorus (phosphate) levels in patients who are on dialysis due to severe kidney disease. Dialysis removes some phosphate from your blood, but it is difficult to remove enough to keep your phosphate levels balanced. By decreasing blood phosphate levels one could help keep bones strong, prevent unsafe buildup of minerals in body, and possibly decrease the risk of heart disease and strokes that can result from high phosphate levels. Belmar works by holding onto phosphate from the diet so that it can pass out of your body safely without entering your blood stream.