What is the weekly dosage regimen for Ergocalciferol (Vitamin D2)?

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From the Guidelines

Ergocalciferol can be taken once a week as a high-dose supplement for treating vitamin D deficiency, with a typical weekly dosage of 50,000 IU, usually prescribed for 8 weeks followed by a recheck of the serum 25(OH)D level and subsequent dosing based on the results 1.

Key Considerations

  • The weekly regimen is often preferred over daily dosing because it improves adherence and can rapidly correct severe deficiency.
  • After completing the initial treatment course, patients typically transition to a lower maintenance dose, either weekly or daily (1,000-2,000 IU daily or equivalent weekly dose).
  • The once-weekly dosing works because vitamin D is fat-soluble and stored in body tissues, allowing for less frequent administration.
  • Patients should take ergocalciferol with food containing some fat to enhance absorption.
  • Blood levels should be monitored after 8-12 weeks of therapy to assess response and adjust dosing as needed.
  • Side effects are rare but can include hypercalcemia at very high doses.

Dosage and Administration

  • The recommended dosage for ergocalciferol is 50,000 IU weekly for 8 weeks, followed by a recheck of the serum 25(OH)D level and subsequent dosing based on the results 1.
  • Alternative dosing regimens include 50,000 IU twice a month or 1000 IU daily, depending on the severity of the deficiency and patient response 1.

Monitoring and Adjustment

  • Serum 25(OH)D levels should be monitored after 8-12 weeks of therapy to assess response and adjust dosing as needed.
  • Patients with severe deficiency may require more frequent monitoring and dose adjustments.
  • The goal of treatment is to achieve a serum 25(OH)D level of 30 ng/mL or higher, which is associated with optimal bone health 1.

From the Research

Ergocalciferol Dosage

  • Ergocalciferol is often prescribed once a week, with a common dosage of 50,000 IU/week 2
  • A study found that 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 2
  • Another study used a dosage of 72,000 IU/week for 12 weeks, followed by 24,000 IU/week as maintenance therapy, to correct vitamin D deficiency/insufficiency in hemodialysis patients 3

Safety and Efficacy

  • A case report found no toxicity after massive doses of ergocalciferol (150,000 IU orally daily) for 28 years 4
  • A study found that an ergocalciferol regimen of 50,000-100,000 IU/week with no loading dose could be considered as a starting point for vitamin D repletion 2
  • High-dose vitamin D2 supplementation was found to be safe and sufficient to obtain and maintain optimal serum 25(OH)D concentrations in chronic kidney disease patients on dialysis 3

Vitamin D Deficiency and Supplementation

  • Vitamin D deficiency is associated with unfavorable skeletal outcomes, including fractures and bone loss 5
  • A 25(OH)D level of >50 nmol/L or 20 ng/ml is the primary treatment goal, although some data suggest a benefit for a higher threshold 5
  • Vitamin D supplementation may be beneficial, but the intake of vitamin D should be under the supervision of health professionals because overdosing leads to intoxication with severe health consequences 6

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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