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 cholecalciferol (vitamin D3) daily for 12 weeks, or alternatively 50,000 IU every other week for 12 weeks, followed by maintenance therapy with 600 IU daily for children aged 1-18 years. 1

Initial Treatment Phase (Loading Dose)

The treatment approach depends on the severity of deficiency and the child's age:

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

• Children 1-18 years: Administer 2,000 IU daily for 12 weeks OR 50,000 IU every other week for 12 weeks 1
• Infants <1 year: Smaller doses are likely sufficient, though specific pediatric dosing is not well-established; consider 400-1,000 IU daily 1
• Goal: Achieve 25-OH-D level above 20 ng/mL (50 nmol/L) 1

For Mild Deficiency (5-15 ng/mL):

• Alternative regimen: 4,000 IU daily orally for 12 weeks OR 50,000 IU every other week for 12 weeks 1

Cholecalciferol (vitamin D3) is strongly preferred over ergocalciferol (vitamin D2) due to higher bioefficacy and longer maintenance of serum levels. 1

Maintenance Phase

After completing the 12-week loading phase:

• Infants 0-12 months: 400 IU daily from all sources 1, 2
• Children and adolescents 1-18 years: 600 IU daily from all sources 1, 2
• Preterm infants on parenteral nutrition: 200-1,000 IU daily (or 80-400 IU/kg/day) 1

These maintenance doses are recommended by the American Academy of Pediatrics, ESPGHAN, and the Institute of Medicine. 1

Essential Co-Interventions

Ensure adequate calcium supplementation during treatment:

• Calcium dose: 250-500 mg/day of elemental calcium 3, 1
• This is particularly critical in children with low ionized calcium or elevated PTH at baseline 1
• Adequate calcium is necessary for vitamin D to support bone mineralization and prevent hypocalcemia 1

Monitoring Protocol

Initial Monitoring:

• Recheck 25-OH-D levels after 12 weeks of treatment to confirm normalization 1
• Consider evaluating serum calcium, phosphorus, alkaline phosphatase, and PTH levels 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 long-term parenteral nutrition, monitor periodically and provide additional supplementation if 25-OH-D falls below 50 nmol/L 1

Special Populations Requiring Modified Approach

Children with Nephrotic Syndrome:

• Monitor ionized calcium, 25-OH-D3, and PTH levels closely due to massive urinary losses of vitamin D-binding protein 3
• Supplement with oral cholecalciferol or calcifediol PLUS calcium (250-500 mg/day) when levels are low or PTH is elevated 3
• Reduced ionized calcium and elevated PTH indicate the need for both vitamin D and calcium supplementation 3

Children with Malabsorption:

• Consider higher doses or intramuscular administration if oral supplementation fails 1
• Conditions requiring special consideration include inflammatory bowel disease, celiac disease, cystic fibrosis, and post-bariatric surgery 1

Children with Chronic Kidney Disease (Stages 3-4):

• Use standard nutritional vitamin D replacement with cholecalciferol or ergocalciferol 1
• Never use active vitamin D analogs (calcitriol, alfacalcidol, doxercalciferol, paricalcitol) to treat nutritional vitamin D deficiency 1
• Monitor calcium and phosphorus closely to avoid hypercalcemia 1

Children with Clinical Rickets:

• At severe deficiency levels, assess for clinical manifestations of rickets including bone deformities 1
• Consider orthopedic consultation for severe bone deformities that may require surgical intervention after metabolic correction 1
• Evaluate for secondary hyperparathyroidism; if PTH remains elevated despite vitamin D repletion, increase the dose and ensure adequate calcium supplementation 1

Safety Considerations

Upper Tolerable Limits (to prevent toxicity):

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

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

Critical Pitfalls to Avoid

• Do not use active vitamin D analogs to treat nutritional vitamin D deficiency, as they bypass normal regulatory mechanisms and do not correct 25-OH-D levels 1
• Ensure adherence to the treatment regimen, as inconsistent supplementation is a common reason for treatment failure 1
• Avoid excessive supplementation, though vitamin D toxicity is rare at recommended doses 1
• Do not compromise caloric intake with fluid restriction in children with nephrotic syndrome 3
• Monitor for hypercalcemia during treatment, especially in children receiving high-dose supplementation 1

Expected Clinical Outcomes

• Anti-fall efficacy starts with achieved 25-OH-D levels of at least 24 ng/mL 4
• Anti-fracture efficacy starts with achieved 25-OH-D levels of at least 30 ng/mL 4
• The standard 2,000 IU daily or 50,000 IU every other week regimen for 12 weeks should normalize vitamin D levels in most children with deficiency 1