All peritoneal dialysis (PD) solutions are designed to remove toxins and water, normalize the blood electrolyte profile, and provide alkali to help maintain acid-base balance. Different formulations, however, may have different effects upon nutrition status. Solutions with 40, as opposed to 35, mEq/l of sodium lactate have been found to promote weight and muscle mass gain and reduce hospitalization in malnourished PD patients. Glucose is varied to produce solutions with different ultrafiltration potential. The glucose absorbed from the PD solution has a protein-sparing effect. The high glucose concentrations necessary for sustained ultrafiltration over a long dialysis dwell, however, often produce appetite suppression and metabolic abnormalities. Solutions formulated with glucose polymers, instead of hypertonic glucose, may provide sustained ultrafiltration over long dwells with lower carbohydrate absorption and perhaps fewer metabolic effects. Amino acids can also be substituted for glucose at relatively low concentrations. A number of studies have shown that amino acids absorbed from the dialysis solution can provide nutritional benefit to malnourished PD patients.