Effect of Zinc Supplementation on Weight and Food Intake in Patients under Hemodialysis

Poor appetite is one of the nutritional problems of hemodialysis patients. We examined the effect of zinc supplementation on weight and dietary intakes in hemodialysis patients. In a single-blind randomized clinical trial, 61 hemodialysis patients were recruited and randomly divided into two groups of zinc supplements (capsules containing 50 mg elemental zinc) and control (placebo capsules containing cornstarch). The intervention lasted for 60 days. Thirty-eight patients (17 in zinc supplements and 21 in theplacebo group) completed the study. Weight, blood pressure, biochemical parameters including serum calcium, phosphorus, potassium, sodium, blood urine nitrogen, and creatinine were measured and 24-hour food recalls were obtained before and after the intervention. Weight of the subjects in the zinc group increased (2.4, 95% CI: -1.6 to 6.5 kg) and that of the control decreased (-0.85, 95% CI: -2.9 to 1.2 kg) during the intervention. Although none of these alterations was significant, the difference between the two groups was statistically significant. Changes in biochemical parameters and blood pressure were not significantly different between the two groups. The intake of protein (12.7% vs. 8.6% for zinc vs. control), carbohydrate (13.8% vs. 3.0% for zinc vs. control), and energy (8.9% vs. 4.7% for zinc vs. control) increased in both groups, although there was no significant difference between the groups. It was shown that zinc supplementation may increase weight gain and food intake in hemodialysis patients.