What is the recommended dosage of Ergocalciferol for treating vitamin D deficiency?

Recommended Dosage of Ergocalciferol for Treating Vitamin D Deficiency

For vitamin D deficiency treatment, ergocalciferol (vitamin D2) should be prescribed at 50,000 IU weekly for 8 weeks for severe deficiency, while mild deficiency can be treated with 8,000 IU daily for 4 weeks followed by 4,000 IU daily for 2 months. 1

Treatment Regimens Based on Deficiency Severity

The recommended dosage varies according to the severity of vitamin D deficiency:

• Severe deficiency (<5 ng/mL):

  • 50,000 IU weekly for 8-12 weeks 1

• Mild deficiency (5-15 ng/mL):

  • 8,000 IU daily for 4 weeks, then 4,000 IU daily for 2 months 1
  • Alternative: 50,000 IU weekly for 4 weeks, then 50,000 IU twice monthly for 2 months 1

• Insufficiency (16-30 ng/mL):

  • 4,000 IU daily for 12 weeks 1
  • Alternative: 50,000 IU every other week for 12 weeks 1

Maintenance Therapy

After achieving normal vitamin D levels:

• 2,000 IU daily or 50,000 IU monthly 1
• Alternative maintenance: 800-2,000 IU daily 1, 2

Special Population Considerations

Different dosing may be required for specific patient populations:

• Chronic Kidney Disease (CKD) patients:

  • Higher doses may be required 1
  • Note: Cholecalciferol (D3) is preferred over ergocalciferol (D2) in CKD patients due to higher bioefficacy 1
  • High-dose ergocalciferol has shown effectiveness in CKD patients, with double the K/DOQI recommended dose showing significant improvement in vitamin D levels and reduction in PTH levels 3

• Elderly patients (>60 years):

  • 800-1,000 IU daily 1

• Obese patients or those with malabsorption:

  • Higher doses: 50,000 IU weekly or 30,000 IU twice weekly for 6-8 weeks 1

Monitoring and Follow-up

• Recheck 25(OH)D levels 3 months after initiating treatment 1
• Monitor serum calcium and phosphorus levels regularly, especially in CKD patients 1
• Annual monitoring recommended, preferably at the end of darker months 1
• Target 25(OH)D level: ≥30 ng/mL (75 nmol/L) 1
• Optimal range for recurrent deficiency: 40-60 ng/mL 1

Calcium Supplementation

• Ensure adequate calcium intake (800-1,200 mg/day) unless contraindicated 1
• Age-specific recommendations:
  • Under 50 years: 1,000 mg daily
  • Over 50 years: 1,200 mg daily
  • Safe upper limit: 2,500 mg per day 1

Safety and Toxicity Considerations

• Vitamin D toxicity is rare but can occur with daily doses >50,000 IU that produce 25(OH)D levels >150 ng/mL 1
• Signs of toxicity include hypercalcemia, hypercalciuria, dizziness, and renal dysfunction 1
• The upper safety limit for 25(OH)D is generally considered to be 100 ng/mL 1
• Interestingly, a case report documented a patient who received 150,000 IU of ergocalciferol daily for 28 years without toxicity, suggesting significant individual variation in vitamin D metabolism 4

Alternative Regimens

Research has shown that various dosing regimens can be effective:

• Weekly dosing of 60,000 IU may have slight advantages over other regimens when replenishing vitamin D stores 5
• For long-term supplementation, smaller regular doses such as 1,000 IU daily or 10,000 IU weekly are suitable 5
• Patients prescribed 50,000-100,000 IU/week were significantly more likely to attain vitamin D sufficiency compared to those prescribed less than 50,000 IU/week 6
• Loading doses did not significantly increase the odds of attaining sufficiency 6

Common Pitfalls to Avoid

• Failing to adjust dosage based on severity of deficiency
• Not considering patient-specific factors like obesity, age, or kidney function
• Inadequate monitoring of 25(OH)D levels after initiating treatment
• Overlooking the need for calcium supplementation alongside vitamin D
• Not recognizing that patients with higher BMI (≥30 kg/m²) may require higher doses to achieve sufficiency 6