What is the management for pediatric patients with hypercalcemia due to high vitamin D and calcium levels?

Management of Hypercalcemia Due to High Vitamin D and Calcium Levels in Pediatric Patients

The management of pediatric hypercalcemia due to high vitamin D and calcium levels should focus on discontinuing vitamin D intake, increasing hydration, and implementing specific pharmacological interventions based on severity.

Initial Assessment and Diagnosis

• Classify severity of hypercalcemia as mild (>5.0 to <5.5 mEq/L), moderate (5.5 to 6.0 mEq/L), or severe (>6.0 mEq/L or >14.0 mg/dL) 1
• Obtain serum calcium (total and ionized), albumin, intact parathyroid hormone (iPTH), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, serum phosphorus, magnesium, blood urea nitrogen, and creatinine 1
• Check urine calcium/creatinine ratio to assess for hypercalciuria 2
• Serum 25-hydroxyvitamin D levels above 150 ng/ml are considered vitamin D intoxication 3

Immediate Management

• Discontinue all vitamin D supplements and calcium-containing medications immediately 3, 4
• Implement a low-calcium and low-phosphorus diet 3
• For severe hypercalcemia (>14 mg/dL), emergency intervention is necessary due to potential adverse effects on cardiac, central nervous system, renal, and gastrointestinal functions 3

Hydration and Diuresis

• Initiate aggressive intravenous hydration with normal saline (0.9% sodium chloride) to increase calcium excretion 4, 5
• Administer loop diuretics (furosemide) after adequate hydration to enhance urinary calcium excretion 3, 5
• Monitor fluid balance carefully to prevent volume overload, especially in younger children 4

Pharmacological Interventions

• For moderate to severe hypercalcemia:
  • Administer glucocorticoids (prednisone) to decrease intestinal calcium absorption and vitamin D activity 3, 4
  • Consider calcitonin for rapid but short-term reduction of serum calcium levels 3, 6
  • In severe cases refractory to other treatments, bisphosphonates (pamidronate) may be used 5

Monitoring and Follow-up

• Monitor serum calcium, phosphorus, and vitamin D levels frequently until normalization 2
• Perform renal ultrasonography to evaluate for nephrocalcinosis, especially if hypercalciuria is present 2
• Continue monitoring calcium levels every 4-6 months until 2 years of age, then every 2 years thereafter in susceptible children 2
• Since vitamin D is stored in fat tissues, effects of toxicity may last for months despite removal of the exogenous source 3

Special Considerations

• In infants diagnosed through family screening or with mild phenotypes, use lower doses of vitamin D if supplementation is required 2
• Avoid multivitamin preparations containing vitamin D in early childhood for children at risk of hypercalcemia 2
• Treatment duration may vary from 6 weeks to 6 months to correct elevated serum calcium, with time to resolution related to age and peak serum calcium 7

Referrals

• Refer to a pediatric nephrologist and/or pediatric endocrinologist for management of persistent hypercalcemia, hypercalciuria, or nephrocalcinosis 2
• For severe cases requiring dialysis or intensive care, consult with pediatric intensive care specialists 5

Prevention

• Educate parents about appropriate vitamin D dosing and the dangers of excessive supplementation 3, 4
• Question parents of all infants about dietary or oral supplement use, with serial questioning during supplementation to avoid excessive intake 3
• Ensure vitamin D deficiency is properly diagnosed with serum 25OHD level before initiating treatment 3