Hypercalcemia is total serum Ca > 12 mg/dL (> 3 mmol/L) or ionized Ca > 6 mg/dL (> 1.5 mmol/L). The most common cause is iatrogenic. GI signs may occur (eg, anorexia, vomiting, constipation) and sometimes lethargy or seizures. Treatment is IV normal saline plus furosemide and sometimes corticosteroids, calcitonin, and bisphosphonates.
The most common cause is
Iatrogenic causes usually involve excess Ca or vitamin D, or phosphate deprivation, which can result from prolonged feeding with incorrectly prepared formula or from dairy milk containing excess vitamin D.
Other causes include maternal hypoparathyroidism, subcutaneous fat necrosis, parathyroid hyperplasia, abnormal renal function, Williams syndrome, and idiopathic. Williams syndrome includes supravalvular aortic stenosis, an elfin facies, and hypercalcemia of unknown pathophysiology; infants may also be small for gestational age, and hypercalcemia can be noted early in infancy, usually resolving by age 12 mo. Idiopathic neonatal hypercalcemia is a diagnosis of exclusion and is difficult to differentiate from Williams syndrome. Neonatal hyperparathyroidism is very rare. Subcutaneous fat necrosis may occur after major trauma and causes hypercalcemia that usually resolves spontaneously. Maternal hypoparathyroidism or maternal hypocalcemia may cause secondary fetal hyperparathyroidism, with changes in fetal mineralization (eg, osteopenia).
Symptoms and Signs
Symptoms and signs may be noted when total serum Ca is > 12 mg/dL (> 3 mmol/L). These signs can include anorexia, GI reflux, nausea, vomiting, lethargy or seizures or generalized irritability, and hypertension. Other symptoms and signs include constipation, abdominal pain, dehydration, feeding intolerance, and failure to thrive. Some neonates have vague symptoms of muscle or joint aches and weakness. With subcutaneous fat necrosis, firm purple nodules may be observed on trunk, buttocks, or legs.
Diagnosis is made by measuring total serum Ca concentration.
Marked elevation of serum Ca may be treated with normal saline 20 mL/kg IV plus furosemide 2 mg/kg IV and, when persistent, with corticosteroids and calcitonin. Bisphosphonates are also increasingly used in this context (eg, etidronate by mouth or pamidronate IV). Treatment of subcutaneous fat necrosis is with a low-Ca formula; fluids, furosemide, calcitonin, and corticosteroids are used as indicated by the degree of hypercalcemia. Fetal hypercalcemia caused by maternal hypoparathyroidism can be treated expectantly, because it usually resolves spontaneously within a few weeks. Treatment of chronic conditions includes a low-Ca, low-vitamin D formula.
Last full review/revision December 2009 by Nicholas Jospe, MD