Vitamin D Supplementation Guidelines in Pediatrics
Standard Maintenance Dosing by Age
All infants, children, and adolescents should receive daily vitamin D supplementation starting at hospital discharge, with 400 IU/day for infants 0-12 months and 600 IU/day for children and adolescents 1-18 years. 1, 2
Infants (0-12 months)
- Breastfed infants: Begin 400 IU/day at hospital discharge and continue throughout the breastfeeding period 2, 3
- Formula-fed infants: Provide 400 IU/day until the infant consistently consumes at least 28 ounces (840 mL) of vitamin D-fortified formula daily 2
- Mixed-fed infants: Continue 400 IU/day until reliably consuming at least 28 ounces of formula daily 2
- Alternative approach: Lactating mothers can take 6,400 IU/day, which provides adequate vitamin D to breastfed infants through breast milk 2
Preterm Infants
- Initial dosing: 200-400 IU/day, with some guidelines suggesting up to 800-1,000 IU/day for extremely preterm infants 2
- On parenteral nutrition: 200-1,000 IU/day (or 80-400 IU/kg/day) 4, 1
Children and Adolescents (1-18 years)
Treatment of Vitamin D Deficiency
Mild Deficiency (5-15 ng/mL)
- Option 1: 4,000 IU/day orally for 12 weeks 5, 1
- Option 2: 50,000 IU every other week for 12 weeks 5, 1
- Assess for clinical manifestations of rickets and metabolic bone disease 5
Vitamin D Insufficiency (16-30 ng/mL)
Severe Deficiency (<5 ng/mL)
- Use the mild deficiency treatment regimen 1
- Evaluate serum calcium, phosphorus, alkaline phosphatase, and parathyroid hormone levels to assess for metabolic bone disease 5
- Ensure adequate dietary calcium intake (250-500 mg/day of elemental calcium) during treatment to support bone mineralization and prevent hypocalcemia 5
Post-Treatment Maintenance
- After completing the 12-week treatment phase, transition to maintenance therapy with 600 IU/day for children 1-18 years 5
- Recheck 25(OH)D levels after the 12-week treatment period to confirm normalization 5
- Once normalized, monitor 25(OH)D levels every 6-12 months, especially during winter months 5
Formulation Selection
Cholecalciferol (vitamin D3) is strongly preferred over ergocalciferol (vitamin D2) due to higher bioefficacy and bioavailability. 5, 1, 2
Safety Thresholds and Upper Tolerable Limits
The following age-specific upper limits prevent toxicity 5, 1, 2:
- 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
Toxicity Considerations
- Prolonged daily intake up to 10,000 IU appears safe, but serum concentrations >375 nmol/L are associated with acute hypercalcemia and hyperphosphatemia 5, 1
- Acute vitamin D intoxication is rare and typically results from doses much higher than 10,000 IU/day 1
- Recent cases of intoxication relate to errors in manufacturing, formulation, or prescription, involving high total intake in the range of 240,000 to 4,500,000 IU 6
Target Serum Levels
The treatment goal is to achieve and maintain 25(OH)D levels above 20 ng/mL (50 nmol/L) for bone health. 5, 1, 2
Special Populations
Children on Parenteral Nutrition
- Monitor periodically for vitamin D deficiency 4, 1
- Provide additional supplementation if 25(OH)D levels fall below 50 nmol/L (20 ng/mL) 4, 1
- Consider oral supplementation for patients on partial PN and during weaning from PN 4
- Administer vitamins with lipid emulsion whenever possible to increase stability 4
Children with Chronic Kidney Disease (CKD) Stages 3-5
- May require higher or more frequent supplementation 5, 1
- Monitor calcium and phosphorus levels closely to avoid hypercalcemia 5, 1
- Optimal dosing is not well-established for this population 5
Children with Nephrotic Syndrome
- Monitor ionized calcium, 25-OH-D3, and PTH levels closely due to massive urinary losses of vitamin D-binding protein 5
- Supplement with oral cholecalciferol PLUS calcium (250-500 mg/day) when levels are low or PTH is elevated 5
Children with Bone Deformity (Rickets)
- Evaluate for secondary hyperparathyroidism; if PTH remains elevated despite vitamin D repletion, increase the dose of vitamin D and/or ensure adequate calcium supplementation 5
- Consider orthopedic consultation for severe bone deformities that may require surgical intervention after metabolic correction 5
Monitoring Strategy
Routine Monitoring
- Healthy infants receiving standard supplementation: Routine testing of serum 25-OH vitamin D levels is NOT recommended 2
- Children on long-term PN: Monitor periodically for deficiency 4, 1
- Children with CKD: Annual monitoring of vitamin D levels 5
High-Risk Populations Requiring Monitoring
- Children with malabsorption conditions (chronic diarrhea, celiac disease, inflammatory bowel disease, cystic fibrosis) 5, 2
- Children with limited sun exposure, inadequate supplementation, and dark skin pigmentation in northern latitudes 5
- Infants and children receiving long-term vitamin D supplementation at or above the upper tolerable intake 6
Monitoring Frequency
- At or above upper tolerable limits: Monitor serum 25(OH)D levels every 3-6 months 5
- After dosage changes: Check levels 3-6 months after any dosage change 5
- Standard maintenance doses (400 IU/day): Annual monitoring is sufficient 5
Common Pitfalls and How to Avoid Them
- Do not delay supplementation until the first outpatient visit—begin at hospital discharge 2
- Do not assume formula-fed infants receive adequate vitamin D until they consistently consume ≥28 ounces daily 2
- Ensure adherence to the treatment regimen, as inconsistent supplementation is a common cause of treatment failure 5, 2
- Avoid excessive supplementation, as vitamin D toxicity can occur, though it's rare at recommended doses 5
- Do not use active vitamin D analogs (such as calcitriol) to treat nutritional vitamin D deficiency 5
- Do not compromise caloric intake with fluid restriction in children with nephrotic syndrome, as this can exacerbate vitamin D deficiency 5
- Ensure adequate calcium supplementation during treatment (250-500 mg/day of elemental calcium), particularly in children with low ionized calcium or elevated PTH at baseline 5