A retrospective study was done in 86 patients on dialysis in order to evaluate the doses of aluminum hydroxide (OH3 Al) received to achieve a better serum phosphate control. Thirty-seven patients were treated with continuous ambulatory peritoneal dialysis (CAPD) divided in 22 diabetics and 15 non-diabetics. Forty-nine patients were treated with hemodialysis (HD), 12 diabetics and 37 non-diabetics. The doses of 1-25 Dihidroxycholecalciferol (1-25 DOH-D3) were similar in all patients. The serum phosphate levels were similar in CAPD and HD patients with smaller doses of OH3 AL in CAPD patients (p less than 0.001). Diabetics on either technique need less OH3 AL in CAPD (CAPD p less than 0.01; HD p less than 0.05) to achieve the same or better control of serum phosphorus than non-diabetics. The overload of glucose on CAPD and the maintained hyperglycemia on diabetes mellitus would shift phosphorus into the cell and could explain these results. Finally, the less needs of aluminum hydroxide on diabetic patients could contribute to their protection against aluminum deposition and its effects.