What is the recommended vitamin D supplementation regimen for a child with vitamin D deficiency?

Vitamin D Supplementation for Children with Vitamin D Deficiency

For children with vitamin D deficiency, the recommended treatment regimen includes an initial treatment phase with 2,000 IU of vitamin D daily for 12 weeks, followed by maintenance therapy of 600 IU daily for children 1-18 years. 1

Initial Treatment Phase

• For severe vitamin D deficiency, provide a loading dose regimen to rapidly normalize levels: 2,000 IU daily for 12 weeks or 50,000 IU every other week for 12 weeks 1
• The goal of treatment is to achieve serum 25(OH)D levels above 20 ng/mL (50 nmol/L) 2, 1
• Treatment dosing should be adjusted based on age:
  • Preterm infants: 200-1000 IU/day (or 80-400 IU/kg/day) 2
  • Term infants up to 12 months: 400 IU/day (or 40-150 IU/kg/day) 2
  • Children 1-18 years: 400-600 IU/day 2, 3

Maintenance Phase

• After correcting deficiency, continue with maintenance therapy:
  • 400 IU/day for infants 2, 4
  • 600 IU/day for children and adolescents 2, 1
• Oral supplementation should be considered in patients on partial parenteral nutrition as well as during weaning from parenteral nutrition 2

Monitoring

• Measure serum 25(OH)D levels after 6-12 weeks of treatment to assess response 3, 1
• Recheck levels after the initial 12-week treatment period to confirm normalization 1
• Once normalized, monitor 25(OH)D levels every 6-12 months, especially during winter months 1
• Target serum 25(OH)D concentration should be >50 nmol/L (20 ng/mL) 2, 3

Clinical Considerations

• Evaluate for clinical manifestations of rickets in severely deficient children 1
• Consider measuring serum calcium, phosphorus, alkaline phosphatase, and parathyroid hormone levels to assess for metabolic bone disease 1
• Ensure adequate dietary calcium intake during treatment, as vitamin D improves calcium absorption 1
• Children with malabsorption conditions (celiac disease, cystic fibrosis, etc.) may require higher doses 5

Safety Considerations

• Avoid excessive supplementation as vitamin D toxicity can occur 3, 1
• Tolerable upper intake levels by age group:
  • Infants 0-6 months: 1,000 IU/day 2
  • Infants 7-12 months: 1,500 IU/day 2
  • Children 1-3 years: 2,500 IU/day 2
  • Children 4-8 years: 3,000 IU/day 2, 3
  • Children and adolescents 9-18 years: 4,000 IU/day 2
• Prolonged daily intake up to 10,000 IU appears safe, but serum concentrations >375 nmol/L are associated with acute hypercalcemia and hyperphosphatemia 2

Prevention of Vitamin D Deficiency

• All infants, children, and adolescents should have a minimum daily intake of 400 IU of vitamin D 6, 4
• Encourage healthy lifestyle habits including adequate sun exposure and dietary sources of vitamin D 7
• Risk factors for deficiency include winter season, insufficient time outdoors, non-white ethnicity, obesity, low milk consumption, and advanced puberty 6