Vitamin D Dosage Recommendations for Deficiency
For vitamin D deficiency, adults should receive 50,000 IU weekly for 4-8 weeks followed by maintenance therapy of 2,000 IU daily, while children's dosing should be based on severity of deficiency. 1
Dosage Recommendations Based on Deficiency Severity
Adults
- Severe deficiency (<5 ng/mL): 8,000 IU daily for 4 weeks or 50,000 IU weekly for 4 weeks, then maintenance therapy 1
- Mild deficiency (5-15 ng/mL): 50,000 IU weekly for 4-8 weeks, then maintenance therapy 1
- Insufficiency (16-30 ng/mL): 2,000 IU daily or 50,000 IU every 4 weeks 1
- Maintenance therapy: 800-2,000 IU daily after correction of deficiency 1, 2
Children
While specific pediatric dosing wasn't fully detailed in the guidelines, the general approach should follow similar principles with age-appropriate adjustments:
- The Dietary Reference Intake (DRI) for prevention of vitamin D deficiency in children is at least 400 IU daily 3
- For treatment of deficiency, dosing should be adjusted based on severity and age
Special Populations Requiring Higher Doses
- Obesity: 2-3 times higher doses (up to 7,000 IU daily) due to sequestration in adipose tissue 1, 4
- Malabsorption syndromes: 50,000 IU 1-3 times weekly 1
- Bariatric surgery patients: 3,000-6,000 IU daily 1
- Liver disease: Higher doses due to impaired hepatic 25-hydroxylation 1, 4
- Elderly (≥65 years): At least 800 IU daily 1
- Dark-skinned or veiled individuals: At least 800 IU daily 1
Formulation Considerations
- Cholecalciferol (vitamin D3) is preferred over ergocalciferol (vitamin D2) due to higher bioefficacy 3, 1
- Available as 50,000 IU capsules for weekly dosing or lower-dose formulations for daily use 5
Monitoring Recommendations
- Check serum calcium and phosphorus levels monthly for the first 3 months, then every 3 months 1
- Target 25(OH)D level is 30-80 ng/mL 1
- Vitamin D toxicity is rare and typically occurs with much higher doses (>10,000 IU daily for extended periods) 1
Important Considerations
- Adequate calcium intake (1000-1500 mg daily) is necessary alongside vitamin D supplementation 1
- Take vitamin D supplements with food to enhance absorption 5
- For long-term maintenance in high-risk individuals without monitoring, 7,000 IU daily or 30,000 IU weekly can be considered 4
- The response to vitamin D supplementation varies based on starting 25(OH)D level, BMI, age, and albumin concentration 6
Cautions
- Avoid single large doses of 300,000-500,000 IU as they may increase fracture risk 7
- Do not initiate therapy if serum calcium is elevated or kidney function is rapidly worsening 1
- Monitor for complications including hypercalcemia and hyperphosphatemia 1
- Vitamin D supplements are contraindicated in patients with hypercalcemia or hypervitaminosis D 5
Following these evidence-based recommendations will help effectively treat vitamin D deficiency while minimizing risks of under or over-supplementation.