What is the recommended vitamin D treatment for patients with end-stage kidney disease?

Vitamin D Treatment in End-Stage Kidney Disease

For patients with end-stage kidney disease, the recommended vitamin D treatment includes calcimimetics, calcitriol, or vitamin D analogues (such as paricalcitol or doxercalciferol), or a combination of calcimimetics with calcitriol or vitamin D analogues, with selection based on serum calcium, phosphorus, and PTH levels. 1

Types of Vitamin D Therapy in ESKD

• Nutritional Vitamin D: Supplementation with ergocalciferol or cholecalciferol is recommended for patients with vitamin D deficiency (25(OH)D <30 ng/mL) 2
• Active Vitamin D Sterols: For patients with elevated PTH levels (>300 pg/mL), active vitamin D compounds are recommended 1
  • Calcitriol
  • Alfacalcidol
  • Paricalcitol
  • Doxercalciferol

Indications for Active Vitamin D Therapy

• PTH Levels: Treatment with active vitamin D sterols is indicated when intact PTH levels exceed 300 pg/mL in dialysis patients 1
• Prerequisite Laboratory Values: Treatment should only be initiated when:
  • Serum corrected total calcium <9.5 mg/dL (2.37 mmol/L) 1
  • Serum phosphorus <4.6 mg/dL (1.49 mmol/L) 1

Dosing Guidelines

Hemodialysis Patients:

• Initial Dosing: For adults, the dose in micrograms = baseline iPTH (pg/mL) divided by 80, administered three times weekly 3
• Route: Intravenous administration of calcitriol is more effective than daily oral calcitriol in lowering serum PTH levels 1

Peritoneal Dialysis Patients:

• Oral Dosing Options:
  • Calcitriol: 0.5 to 1.0 μg, 2-3 times weekly, or 0.25 μg daily 1
  • Doxercalciferol: 2.5 to 5.0 μg, 2-3 times weekly 1

Monitoring Parameters

• Calcium and Phosphorus: Monitor every 2 weeks for 1 month after initiation or dose change, then monthly 1
• PTH: Measure monthly for at least 3 months, then every 3 months once target levels are achieved 1
• Target PTH Range: 150-300 pg/mL for dialysis patients 1

Dose Adjustments

• If PTH falls below target range: Hold therapy until PTH rises above target, then resume at half the previous dose 1
• If calcium exceeds 9.5 mg/dL: Hold therapy until calcium normalizes, then resume at half the previous dose 1
• If phosphorus exceeds 4.6 mg/dL: Hold therapy, increase phosphate binder dose until phosphorus normalizes, then resume prior vitamin D dose 1

Newer vs. Conventional Vitamin D Analogues

• Selective VDR Activators (paricalcitol, maxacalcitol, doxercalciferol) may have advantages over conventional therapy:
  • Less calcemic and phosphatemic effects while maintaining PTH suppression 1
  • Potentially associated with improved survival compared to conventional therapy 4
  • May be considered when calcium or phosphorus levels are elevated 1

Nutritional Vitamin D Supplementation

• Recommendation: Patients with ESKD should be evaluated for vitamin D deficiency 2
• Dosing: Higher doses than general population may be needed (4,000 IU/day vs. 1,000 IU/day) 1
• Benefits: May help reduce PTH levels with minimal effect on calcium and phosphate 1

Dialysate Calcium Considerations

• Recommended concentration: 2.5 mEq/L (1.25 mmol/L) 1
• This concentration helps balance the need for PTH control while minimizing risk of hypercalcemia 1

Potential Adverse Effects and Cautions

• Hypercalcemia: Common side effect of active vitamin D therapy 1
• Hyperphosphatemia: All vitamin D sterols can raise serum phosphorus 1
• Adynamic Bone Disease: Risk increases when PTH is suppressed below 150 pg/mL 1
• Vascular Calcification: May be increased in patients with biochemical features consistent with adynamic bone 1
• Contraindications: Vitamin D therapy should not be initiated or continued if:
  • Serum phosphorus exceeds 6.5 mg/dL 1
  • Patient has rapidly worsening kidney function 1
  • Patient is non-compliant with medications or follow-up 1

Special Considerations

• When using vitamin D analogues, all other forms of vitamin D supplementation should be discontinued if serum calcium exceeds 10.2 mg/dL 2
• Intravenous vitamin D may provide better PTH suppression with lower serum phosphorus and calcium compared to oral administration 5
• Vitamin D therapy may have benefits beyond mineral metabolism, including potential cardiovascular and immune effects 4