Is zinc supplementation safe for patients with End-Stage Renal Disease (ESRD) on dialysis?

Zinc Supplementation in Dialysis Patients

Zinc supplementation should be monitored and provided to dialysis patients when deficiency is confirmed through laboratory testing, as patients on dialysis are at risk for zinc deficiency due to dialysis-related losses. 1

Zinc Status in Dialysis Patients

Dialysis patients are at particular risk for alterations in trace element levels, including zinc, due to several factors:

• Decreased dietary intake related to anorexia or dietary restrictions
• Increased clearance from blood during dialysis sessions
• Loss of zinc in dialysis effluent
• Interference with normal zinc absorption and metabolism 1

Studies have shown variable zinc status in dialysis patients:

• Low serum zinc levels have been documented in many dialysis patients, particularly those receiving continuous peritoneal dialysis 1
• In some cases, zinc levels may actually increase during hemodialysis sessions, depending on the dialysis equipment used 2
• Approximately 44.1% of chronic hemodialysis patients have been found to be zinc deficient in observational studies 1

Recommendations for Zinc Supplementation

1. Monitor zinc levels: Regular monitoring of serum zinc levels is recommended, especially in:

   • Patients on long-term dialysis
   • Those receiving a low-protein diet
   • Patients showing clinical signs of zinc deficiency 1

2. Supplementation approach:

   • Provide zinc supplementation only when deficiency is confirmed by laboratory testing 1, 3
   • Aim to achieve the Dietary Reference Intake (DRI) for zinc appropriate for age and gender 1
   • For adults, this typically ranges from 8-11 mg/day for males and 8-9 mg/day for females 1

3. Caution with supplementation:

   • Blanket supplementation for all dialysis patients is not recommended 3
   • Some dialysis equipment (particularly certain Cuprophan-membrane coils) may release zinc during dialysis, potentially causing elevated zinc levels 2
   • Excessive zinc supplementation could potentially lead to toxicity 2

Benefits of Zinc Supplementation When Indicated

When zinc deficiency is confirmed, supplementation may provide several benefits:

• Improved antioxidant defense system function 4, 5
• Potential reduction in inflammation markers (C-reactive protein) 4
• May help ameliorate abnormally high plasma aluminum concentrations 5
• Supports immune function and wound healing 1

Clinical Considerations

• A randomized trial showed that moderate supplementation with zinc (50 mg/day) was not sufficient to correct deficiencies in chronic dialysis patients, suggesting higher requirements 1
• However, another study using 100 mg/day of elemental zinc for 3 months did not show improvements in nutritional status parameters in CAPD patients despite normalizing zinc levels 6
• Zinc supplementation should be part of a comprehensive approach to micronutrient management in dialysis patients, which also includes attention to other trace elements like selenium and copper 1

Monitoring During Supplementation

• Regular assessment of serum zinc levels during supplementation
• Monitor for signs of zinc toxicity (nausea, vomiting, epigastric pain, lethargy, and fatigue)
• Reassess clinical symptoms that may be related to zinc deficiency (taste alterations, poor wound healing, skin lesions)

In summary, while zinc supplementation is not universally required for all dialysis patients, those with confirmed deficiency should receive appropriate supplementation to achieve normal zinc status and potentially benefit from improved clinical outcomes.