A dietary supplement which is formulated for medical patients, particularly renal dialysis patients undergoing a peritoneal renal dialysis treatment regimen. The supplement includes a powdered mixture of calcium caseinate, whey protein, L-carnitine and arginine. The ingredients are typically formulated in a powdered form which can be easily added to and ingested with various foods. The supplement provides various nutritional benefits to renal dialysis patients, including the elevation of blood carnitine and albumin levels and the reduction of blood pressure in renal transplant patients.