What is the recommended vitamin D (cholecalciferol) dosing for children with vitamin D deficiency or insufficiency?

Vitamin D Dosing for Children

Maintenance Dosing (Prevention)

For routine supplementation in healthy children, give 400 IU daily for infants under 12 months and 600 IU daily for children and adolescents ages 1-18 years. 1

• Infants 0-12 months require 400 IU/day from all sources (diet plus supplements), as recommended by ESPGHAN, the American Academy of Pediatrics, and the Institute of Medicine 1
• Children and adolescents 1-18 years require 600 IU/day from all sources 1
• Preterm infants on parenteral nutrition need 200-1,000 IU/day (or 80-400 IU/kg/day) 1

Treatment Dosing for Deficiency

For children with documented vitamin D deficiency (25(OH)D <20 ng/mL), treat with 2,000 IU daily for 12 weeks or 50,000 IU every other week for 12 weeks, then transition to maintenance dosing. 1

Deficiency Severity-Based Approach:

• Severe deficiency (5-15 ng/mL): 4,000 IU/day orally for 12 weeks OR 50,000 IU every other week for 12 weeks 1
• Insufficiency (16-30 ng/mL): 2,000 IU daily OR 50,000 IU every 4 weeks 1
• Goal: Achieve 25(OH)D level above 20 ng/mL (50 nmol/L) 1

After Initial Treatment:

• Recheck 25(OH)D levels after the 12-week treatment period to confirm normalization 1
• Transition to maintenance therapy: 600 IU daily for children 1-18 years 1
• Monitor 25(OH)D levels every 6-12 months, especially during winter months 1

Formulation Choice

Use cholecalciferol (vitamin D3) rather than ergocalciferol (vitamin D2), as D3 has higher bioefficacy for treating deficiency. 1

Safety Thresholds - Upper Tolerable Limits

The Institute of Medicine established age-specific maximum safe doses to prevent toxicity 1:

• 0-6 months: 1,000 IU/day maximum
• 7-12 months: 1,500 IU/day maximum
• 1-3 years: 2,500 IU/day maximum
• 4-8 years: 3,000 IU/day maximum
• 9-18 years: 4,000 IU/day maximum

Prolonged daily intake up to 10,000 IU appears safe, but serum concentrations >375 nmol/L are associated with acute hypercalcemia and hyperphosphatemia 1

Concurrent Calcium Supplementation

Provide 250-500 mg/day of elemental calcium during vitamin D treatment to support bone mineralization and prevent hypocalcemia, particularly in children with low ionized calcium or elevated PTH at baseline. 1

This is critical because vitamin D enhances calcium absorption, and adequate calcium intake prevents secondary complications 1

Monitoring Strategy

Baseline Assessment:

• Measure 25(OH)D, calcium, phosphorus, alkaline phosphatase, and parathyroid hormone 1
• Assess for clinical manifestations of rickets at severe deficiency levels 1

Follow-up Monitoring:

• Recheck 25(OH)D after 12 weeks of treatment 1
• Once normalized, monitor every 6-12 months 1
• For children on long-term parenteral nutrition, monitor periodically and provide additional supplementation if 25(OH)D falls below 50 nmol/L 1

Special Populations Requiring Higher Doses

• Children with renal insufficiency: May need higher or more frequent supplementation 1
• Children on parenteral nutrition: Monitor for deficiency and provide additional supplementation if 25(OH)D <50 nmol/L 1
• Children with nephrotic syndrome: Monitor ionized calcium, 25-OH-D3, and PTH levels closely due to massive urinary losses of vitamin D-binding protein 1
• Children with malabsorption syndromes: Often require substantially higher doses 1

Critical Pitfalls to Avoid

• Do not use active vitamin D analogs (calcitriol) to treat nutritional vitamin D deficiency - these are reserved for specific conditions like chronic kidney disease 1
• Ensure adherence to the treatment regimen, as inconsistent supplementation leads to treatment failure 1
• Avoid excessive supplementation, though toxicity is rare at recommended doses 1
• Monitor calcium and phosphorus closely to avoid hypercalcemia, especially in children with CKD 1