What is the treatment for vitamin D deficiency in children?

Vitamin D Deficiency Treatment in Children

For children with vitamin D deficiency, initiate treatment 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

Treatment Algorithm Based on Deficiency Severity

Severe Deficiency (<5 ng/mL)

• Administer 4,000 IU daily for 12 weeks OR 50,000 IU every other week for 12 weeks 1
• This loading dose regimen rapidly normalizes vitamin D levels and addresses potential rickets manifestations 1
• Monitor for clinical signs of rickets including bone pain, proximal muscle weakness, and skeletal deformities 2

Mild to Moderate Deficiency (5-15 ng/mL)

• Give 2,000 IU daily for 12 weeks OR 50,000 IU every 4 weeks 1
• This intermediate dosing achieves sufficiency without excessive supplementation risk 1

Insufficiency (16-30 ng/mL)

• Provide 2,000 IU daily OR 50,000 IU every 4 weeks 1
• Less aggressive repletion is needed compared to frank deficiency 1

Age-Specific Maintenance Therapy (After Initial Treatment)

Once vitamin D levels normalize, transition to maintenance dosing based on age: 1, 3

• Preterm infants: 200-400 IU daily 1
• Term infants (0-12 months): 400 IU daily 1, 3
• Children and adolescents (1-18 years): 600 IU daily 1, 3

The American Academy of Pediatrics, ESPGHAN, and Institute of Medicine all endorse these maintenance recommendations 1.

Formulation Selection

Use cholecalciferol (vitamin D3) rather than ergocalciferol (vitamin D2) because D3 demonstrates superior bioefficacy for treating deficiency 1. This is particularly important for achieving and maintaining target levels efficiently.

Monitoring Strategy

Initial Assessment

• Check baseline 25(OH)D, calcium, phosphorus, alkaline phosphatase, and PTH levels to assess severity and rule out metabolic bone disease 1
• These labs establish the degree of deficiency and identify complications like secondary hyperparathyroidism 1

Follow-Up Testing

• Recheck 25(OH)D after 12 weeks of treatment to confirm normalization (target >20 ng/mL or 50 nmol/L) 1
• Monitor every 6-12 months thereafter, especially during winter months when sun exposure is limited 1
• A recent RCT demonstrated that both daily and fortnightly regimens achieve sufficiency, but compliance is better with less frequent dosing (72.9% vs 59.7%) 4

Safety Monitoring

• Assess serum calcium and urine calcium:creatinine ratio during treatment 4
• Asymptomatic transient hypercalcemia occurred in 34-51% of treated children in one study but resolved spontaneously 4
• Hypercalciuria developed in 5.7% of children on daily dosing 4

Concurrent Calcium Supplementation

Provide 250-500 mg/day of elemental calcium during vitamin D treatment 5. Vitamin D enhances calcium absorption, so adequate dietary calcium is essential to prevent hypocalcemia and support bone mineralization 1. This is particularly critical in children with low ionized calcium or elevated PTH at baseline 5.

Safety Thresholds and Upper Limits

Do not exceed age-specific tolerable upper intake levels: 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

While prolonged daily intake up to 10,000 IU appears safe, serum concentrations >375 nmol/L are associated with acute hypercalcemia and hyperphosphatemia 1. Vitamin D toxicity is rare at recommended treatment doses 1.

Special Population Considerations

Children with Chronic Kidney Disease

• Monitor 25(OH)D levels annually and supplement with vitamin D3 to correct deficiency 3
• Check calcium and phosphorus one month after initiating or changing doses to avoid hypercalcemia 3
• Optimal dosing for CKD stages 3-5 is not well-established, requiring individualized monitoring 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 5, 3
• Supplement with oral cholecalciferol or calcifediol plus calcium (250-500 mg/day) when levels are low or PTH is elevated 5
• Higher or more frequent supplementation may be required due to urinary losses 3

Children on Parenteral Nutrition

• Provide 200-1,000 IU/day for preterm infants and 400 IU/day for term infants 1, 3
• Monitor periodically and provide additional supplementation if 25(OH)D falls below 50 nmol/L 1
• Consider oral supplementation during weaning from parenteral nutrition 1

Critical Pitfalls to Avoid

• Do not use active vitamin D analogs (calcitriol) to treat nutritional vitamin D deficiency 1 — these are reserved for specific conditions like CKD-mineral bone disorder, not simple deficiency
• Ensure treatment adherence as inconsistent supplementation leads to treatment failure 1
• Avoid excessive supplementation beyond recommended doses, though toxicity is rare at therapeutic levels 1
• Do not rely solely on sunlight exposure — an RCT demonstrated oral supplementation achieves sufficiency in 35% vs 14% with sunlight alone, primarily due to better compliance 6