What is the recommended treatment for vitamin D deficiency in pediatric patients?

Treatment of Vitamin D Deficiency in Pediatric Patients

For children with vitamin D deficiency, treat with 2,000 IU of vitamin D3 daily for 12 weeks (or alternatively 50,000 IU every other week for 12 weeks), followed by age-appropriate maintenance dosing of 400-600 IU daily. 1

Initial Treatment Phase (Loading Dose)

The treatment approach depends on the severity of deficiency:

Severe Deficiency (25(OH)D <20 ng/mL)

• Administer 2,000 IU daily for 12 weeks 1
• Alternative regimen: 50,000 IU every other week for 12 weeks 1
• Both regimens provide equivalent cumulative dosing and achieve sufficiency in the majority of children 2

Moderate Deficiency/Insufficiency (25(OH)D 16-30 ng/mL)

• Administer 2,000 IU daily or 50,000 IU every 4 weeks 1

Formulation Choice

• Use cholecalciferol (vitamin D3) rather than ergocalciferol (vitamin D2) due to superior bioefficacy 1
• Do not use active vitamin D analogs (calcitriol) for nutritional vitamin D deficiency 1

Essential Concurrent Calcium Supplementation

Provide 250-500 mg/day of elemental calcium during vitamin D treatment to support bone mineralization and prevent hypocalcemia, particularly critical in children with low ionized calcium or elevated PTH at baseline 1. This is often overlooked but essential for optimal treatment response.

Maintenance Phase (After 12 Weeks)

Once deficiency is corrected, transition to age-appropriate maintenance dosing:

• Infants 0-12 months: 400 IU/day 1
• Children and adolescents 1-18 years: 600 IU/day 1
• Preterm infants: 200-400 IU/day 1

These recommendations come from the American Academy of Pediatrics, ESPGHAN, and Institute of Medicine 1.

Monitoring Strategy

During Treatment

• Recheck 25(OH)D levels after the 12-week treatment period to confirm normalization 1
• Target level: >20 ng/mL (50 nmol/L) for sufficiency 1
• Evaluate serum calcium, phosphorus, alkaline phosphatase, and PTH to assess for metabolic bone disease 1

Long-Term Monitoring

• Monitor 25(OH)D levels every 6-12 months once normalized, especially during winter months when sun exposure is limited 1
• For children on standard maintenance doses (400-600 IU/day), annual monitoring is sufficient 1

Safety Thresholds and Upper Limits

Age-specific upper tolerable limits 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.

Special Populations Requiring Modified Approach

Children with Chronic Kidney Disease

• Optimal dosing for CKD stages 3-5 is not well-established 1
• Monitor calcium and phosphorus closely to avoid hypercalcemia 1
• Consider higher or more frequent supplementation 1

Children with Nephrotic Syndrome

• Monitor ionized calcium, 25(OH)D, and PTH levels closely due to massive urinary losses of vitamin D-binding protein 1
• Supplement with oral cholecalciferol PLUS calcium (250-500 mg/day) when levels are low or PTH is elevated 1

Children with Malabsorption

• Check 25(OH)D levels in children with chronic diarrhea, celiac disease, inflammatory bowel disease, or cystic fibrosis 1
• May require higher doses than standard recommendations 3

Children on Parenteral Nutrition

• Monitor periodically for vitamin D deficiency 1
• Provide additional supplementation if 25(OH)D falls below 50 nmol/L 1
• Consider oral supplementation during weaning from PN 1

Clinical Assessment for Rickets

At severe deficiency levels, assess for clinical manifestations of rickets 1:

• Bone deformities (bowing of legs, rachitic rosary)
• If PTH remains elevated despite vitamin D repletion, increase vitamin D dose and ensure adequate calcium supplementation 1
• Consider orthopedic consultation for severe bone deformities that may require surgical intervention after metabolic correction 1

Critical Pitfalls to Avoid

• Avoid excessive supplementation as vitamin D toxicity can occur, though rare at recommended doses 1
• Ensure adherence to the treatment regimen, as inconsistent supplementation leads to treatment failure 1
• Never use active vitamin D analogs (calcitriol) to treat nutritional vitamin D deficiency 1
• Do not forget calcium supplementation during treatment, as vitamin D improves calcium absorption but requires adequate substrate 1
• Monitor for transient hypercalcemia and hypercalciuria during treatment, which typically resolves spontaneously 2

Practical Considerations

Both daily and intermittent (fortnightly) dosing regimens with equivalent cumulative doses are efficacious 2. The choice between daily (2,000 IU) versus intermittent (50,000 IU every other week) can be based on adherence considerations, with intermittent dosing potentially improving compliance in families struggling with daily medication administration 1, 2.