What is the recommended dose of vitamin D (Vitamin D) for patients with Chronic Kidney Disease (CKD)?

Vitamin D Dosing in Chronic Kidney Disease

For CKD patients with vitamin D deficiency (25(OH)D <30 ng/mL), treat with ergocalciferol 50,000 IU weekly for 4-12 weeks depending on severity, followed by maintenance dosing of 1,000-2,000 IU daily or 50,000 IU monthly. 1

Initial Assessment and Treatment Strategy

Measure Baseline Vitamin D Status

• Check serum 25-hydroxyvitamin D [25(OH)D] at first encounter for all CKD patients stages 3-5, and repeat annually if normal. 1
• Vitamin D insufficiency (80-90% prevalence) is extremely common in CKD due to reduced sun exposure, dietary restrictions, urinary losses in nephrotic syndrome, and impaired endogenous synthesis. 1

Treatment Based on Deficiency Severity

For Severe Deficiency (25(OH)D <5 ng/mL):

• Ergocalciferol 8,000 IU daily orally or enterally for 4 weeks (or 50,000 IU weekly for 4 weeks), then 4,000 IU daily (or 50,000 IU twice monthly) for 2 months. 1

For Mild Deficiency (25(OH)D 5-15 ng/mL):

• Ergocalciferol 4,000 IU daily for 12 weeks (or 50,000 IU every other week for 12 weeks). 1

For Insufficiency (25(OH)D 16-30 ng/mL):

• Ergocalciferol 2,000 IU daily (or 50,000 IU every 4 weeks). 1

Alternative Dosing Recommendations

• K/DOQI guidelines recommend a monthly equivalent of 1,000-2,000 IU/day for CKD patients, which can be achieved with 50,000 IU once monthly. 1
• For northern-dwelling CKD patients, 1,000 IU daily of vitamin D3 (cholecalciferol) significantly increases 25(OH)D levels and reduces insufficiency prevalence by 37%. 2

Critical Distinction: Nutritional vs. Active Vitamin D

When to Use Nutritional Vitamin D (Ergocalciferol/Cholecalciferol)

• Use nutritional vitamin D (ergocalciferol or cholecalciferol) for treating vitamin D deficiency/insufficiency in CKD stages 3-4. 1
• Nutritional vitamin D corrects 25(OH)D levels and may reduce or prevent secondary hyperparathyroidism in early CKD stages. 1
• Do NOT use active vitamin D analogs (calcitriol, alfacalcidol, doxercalciferol, paricalcitol) to treat nutritional vitamin D deficiency. 3

When to Use Active Vitamin D Sterols

• Active vitamin D sterols are indicated only when 25(OH)D is >30 ng/mL AND intact PTH is above target range for the CKD stage. 1
• For CKD stages 3-4: Use active vitamin D sterols (calcitriol, alfacalcidol, or doxercalciferol) only if serum calcium <9.5 mg/dL and phosphorus <4.6 mg/dL. 1
• For CKD stage 5 (dialysis): Active vitamin D sterols indicated when intact PTH >300 pg/mL. 1

Monitoring Requirements

During Nutritional Vitamin D Therapy

• Monitor serum calcium and phosphorus at least every 3 months after initiating ergocalciferol. 1
• Discontinue ergocalciferol if serum calcium exceeds 10.2 mg/dL. 1
• If serum phosphorus exceeds 4.6 mg/dL, add or increase phosphate binder; discontinue vitamin D if hyperphosphatemia persists. 1

During Active Vitamin D Sterol Therapy

• Monitor calcium and phosphorus monthly for first 3 months, then every 3 months thereafter. 1
• Monitor intact PTH every 3 months for 6 months, then every 3 months thereafter. 1

Evidence for Efficacy by CKD Stage

CKD Stage 3

• Ergocalciferol therapy normalizes 25(OH)D levels and produces a median 13.1% decrease in PTH concentrations in stage 3 CKD. 4
• This represents reasonable initial therapy for vitamin D deficiency with elevated PTH in stage 3 CKD. 4

CKD Stage 4

• Ergocalciferol normalizes 25(OH)D levels but produces only a 2.0% (non-significant) decrease in PTH in stage 4 CKD. 4
• Current K/DOQI dosing may be inadequate for correcting secondary hyperparathyroidism in advanced CKD; only 26% of patients achieve ≥30% PTH reduction with standard ergocalciferol dosing. 5

CKD Stage 5 (Dialysis)

• The role of nutritional vitamin D in dialysis patients is controversial due to markedly reduced or absent renal 1α-hydroxylase activity. 1
• However, extrarenal 1α-hydroxylase activity can still generate calcitriol from 25(OH)D, and vitamin D deficiency is associated with more severe secondary hyperparathyroidism even in anephric individuals. 1

Maintenance Therapy

After Achieving Target Levels

• Once vitamin D replete, continue supplementation with a vitamin D-containing multivitamin preparation with annual reassessment of 25(OH)D levels. 1
• Continue monitoring calcium and phosphorus every 3 months. 1

Higher Doses for CKD Population

• For CKD patients with GFR <30 mL/min/1.73m², either supplementing or not supplementing at doses up to 4,000 IU daily are both reasonable based on clinical judgment. 1
• For CKD patients with GFR >30 mL/min/1.73m², follow general population recommendations of 800-1,000 IU daily without routine PTH or vitamin D measurement. 1

Safety Considerations

Upper Dosing Limits

• Daily doses up to 10,000 IU of ergocalciferol have been administered in adult CKD patients for periods longer than 1 year with no evidence of toxicity. 1
• The recommended upper limit is 2,000 IU/day for general population, but CKD patients may require higher doses. 1

Contraindications to Active Vitamin D Sterols

• Do not prescribe active vitamin D sterols for patients with rapidly worsening kidney function or those noncompliant with medications or follow-up. 1

Common Pitfalls to Avoid

• Do not confuse nutritional vitamin D deficiency treatment with active vitamin D sterol therapy for secondary hyperparathyroidism—these are distinct clinical scenarios requiring different interventions. 1
• Do not withhold nutritional vitamin D supplementation in dialysis patients—even with minimal residual renal function, extrarenal conversion occurs and deficiency worsens hyperparathyroidism. 1
• Do not use standard K/DOQI dosing as the ceiling—many CKD patients require higher or more frequent dosing to achieve target 25(OH)D levels ≥30 ng/mL. 5
• Do not start active vitamin D sterols before correcting nutritional vitamin D deficiency—25(OH)D must be >30 ng/mL first. 1