Management of Hypercalcemia in a 16-Year-Old Girl
A calcium level of 2.67 mmol/L (10.7 mg/dL) in a 16-year-old girl represents mild hypercalcemia that requires diagnostic evaluation and appropriate management based on the underlying cause. This level falls within the mild hypercalcemia range (>5.0 to <5.5 mEq/L or <12 mg/dL) 1.
Initial Assessment
- Calculate corrected calcium using the formula: Corrected calcium (mg/dL) = Total calcium (mg/dL) - 0.8 × [Albumin (g/dL) - 4] to confirm true hypercalcemia 1
- Evaluate for symptoms which may include fatigue, constipation, polyuria, polydipsia, nausea, and confusion in mild to moderate cases 1, 2
- Assess hydration status as dehydration can worsen hypercalcemia through decreased renal clearance 2
Diagnostic Workup
Order first-line laboratory tests including:
- Serum albumin (for corrected calcium calculation) 3
- Intact parathyroid hormone (iPTH) - most important initial test to distinguish PTH-dependent from PTH-independent causes 3, 2
- Serum creatinine and blood urea nitrogen to assess renal function 3
- Serum phosphorus and magnesium levels 3
- 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels 3, 4
Check urine calcium/creatinine ratio to evaluate for hypercalciuria 4, 1
If hypercalciuria is present, perform renal ultrasonography to evaluate for nephrocalcinosis 4
Management Approach
For Mild Asymptomatic Hypercalcemia
- Increase oral hydration to enhance renal calcium excretion 1
- Avoid calcium supplements and foods with high calcium content 4
- Avoid vitamin D supplements containing glucose-based sweeteners given potential dental fragility in patients with hypercalcemia 4
- Maintain normal dietary calcium intake (not restricted) unless specifically indicated 5
For Symptomatic or Progressive Hypercalcemia
- Provide intravenous hydration with normal saline if symptoms are present 5, 2
- Consider bisphosphonate therapy (pamidronate or zoledronic acid) for severe or symptomatic hypercalcemia 6, 7
- Administer calcitonin for immediate short-term management of severe symptomatic hypercalcemia 8
Special Considerations for Adolescents
- In pediatric patients, hypercalcemia may be associated with Williams syndrome, which requires monitoring calcium levels every 4-6 months until 2 years of age, then every 2 years 4
- For adolescents with hypercalcemia, treatment with a low-calcium diet and increased water intake under medical and nutritional supervision is often successful 4
- Avoid multivitamin preparations containing vitamin D in early childhood, and use vitamin D supplementation with caution in older children 4
Follow-up and Monitoring
- Monitor serum calcium, renal function, and electrolytes regularly to assess treatment effectiveness 5
- Perform periodic assessment of bone mineral density as approximately 50% of individuals with hypercalcemia may have impaired bone mineral status (osteopenia or osteoporosis) 4
- For patients requiring bisphosphonate therapy, monitor for potential complications including renal toxicity and hypocalcemia post-treatment 1
Common Pitfalls to Avoid
- Do not administer phosphate supplements together with calcium supplements or foods with high calcium content, as precipitation in the intestinal tract reduces absorption 4
- Avoid excessive vitamin D supplementation which can worsen hypercalcemia 4, 9
- Do not overlook the possibility of secondary hyperparathyroidism, which might aggravate phosphaturia and promote bone resorption 4
- Remember that hypercalcemia in adolescents may have different etiologies than in adults, with genetic causes being more common 10