Iron and Multivitamin Supplementation in CKD Stage 5
Yes, CKD stage 5 patients should receive both iron supplementation and multivitamins, but with specific formulations and critical restrictions that differ from the general population. 1, 2
Iron Supplementation in CKD Stage 5
Intravenous iron is the preferred route for all CKD stage 5 patients, particularly those on hemodialysis. 3, 4
Route of Administration
- For hemodialysis patients (CKD 5D), intravenous iron is definitively superior to oral iron, producing significantly greater hemoglobin increases with better tolerability 4
- Oral iron is poorly absorbed in CKD stage 5 patients and causes high rates of gastrointestinal side effects 4
- Intravenous iron is recommended for all CKD patients on dialysis receiving erythropoiesis-stimulating agents 4
Iron Deficiency Criteria (Different from General Population)
- Absolute iron deficiency in hemodialysis patients is defined as transferrin saturation (TSAT) ≤20% AND serum ferritin ≤200 ng/mL (note: this is higher than the ≤100 ng/mL threshold for predialysis patients) 3
- Functional iron deficiency occurs when TSAT ≤20% despite elevated ferritin levels, due to increased hepcidin blocking iron availability 3
Clinical Rationale
- Iron deficiency anemia is associated with increased morbidity and mortality in CKD patients 3
- The severity of anemia correlates with mortality risk 3
- Iron supplementation improves erythropoietic response and may reduce ESA requirements 5, 4
Multivitamin Supplementation in CKD Stage 5
CKD stage 5 hemodialysis patients with inadequate dietary intake should receive renal-specific multivitamins containing water-soluble vitamins and essential trace elements. 1, 2
What to Include
- Water-soluble vitamins (B vitamins including folic acid and B12) to replace dialysis losses 2
- Vitamin C: 90 mg/day for men, 75 mg/day for women, but never exceed 500 mg/day to avoid oxalate accumulation 1, 2
- Vitamin D (cholecalciferol or ergocalciferol) to target 25(OH)D levels ≥30 ng/mL 1, 2
- Essential trace elements as part of the multivitamin formulation 1, 2
Critical Exclusions (Avoid These)
- Never supplement Vitamin A in CKD stage 5 patients—it accumulates to toxic levels and is not removed by dialysis 2
- Never supplement Vitamin E routinely due to toxicity risk in advanced CKD 2
- Never supplement Vitamin K if the patient is on warfarin—this directly antagonizes anticoagulation 1, 6
- Do not routinely supplement selenium or zinc—there is insufficient evidence of benefit 2
Common Pitfalls to Avoid
- Most critical error: Giving vitamin K to any patient on warfarin 1, 6
- Second critical error: Supplementing vitamin A in CKD stage 5 patients 2
- Third critical error: Using oral iron instead of intravenous iron in hemodialysis patients 4
- Exceeding 500 mg/day of vitamin C, which increases oxalate toxicity risk 2
- Assuming standard multivitamins are appropriate—use renal-specific formulations that exclude vitamins A and E 2
Monitoring Strategy
- Assess vitamin status periodically with clinical symptoms and laboratory levels 2
- Monitor iron parameters (TSAT, ferritin) to guide iron dosing 3
- Evaluate nutritional status at minimum 3-month intervals, then every 6-12 months for stable patients 1
- Monitor for potential toxicity, particularly with fat-soluble vitamins 2