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Hypercalcemia in newborns
Medical expert of the article
Last reviewed: 05.07.2025
Hypercalcemia is defined as total serum calcium greater than 12 mg/dL (3 mmol/L) or ionized calcium greater than 6 mg/dL (1.5 mmol/L). The most common cause is iatrogenia. Gastrointestinal signs (anorexia, vomiting, constipation) and sometimes lethargy or seizures may occur. Treatment of hypercalcemia is based on intravenous saline with furosemide and sometimes bisphosphonates.
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What causes hypercalcemia?
The most common causes of hypercalcemia are iatrogenia due to excess calcium or vitamin D, or inadequate phosphorus intake, which may result from prolonged feeding with poorly formulated formula or milk with high vitamin D content. Other causes include maternal hypoparathyroidism, subcutaneous fat necrosis, parathyroid hyperplasia, renal dysfunction, Williams syndrome, and there are cases of idiopathic hypercalcemia. Williams syndrome includes supravalvular aortic stenosis, elfin facies, and hypercalcemia of unknown origin; infants may also be small for gestational age, and hypercalcemia may be present in the first months of life, usually resolving by 12 months of age. 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 significant trauma and cause hypercalcemia, which usually resolves spontaneously. Maternal hypoparathyroidism or hypocalcemia may cause secondary hyperparathyroidism in the fetus, with changes in mineralization such as osteopenia.
Symptoms of hypercalcemia
Symptoms of hypercalcemia may be seen when the total serum calcium level is greater than 12 mg/dL (> 3 mmol/L). These manifestations may include anorexia, regurgitation, vomiting, lethargy or seizures, or generalized irritability and hypertension. Other symptoms of hypercalcemia include constipation, dehydration, impaired food tolerance, and failure to thrive. Firm, violaceous nodules may be seen in subcutaneous necrosis of the trunk, buttocks, and legs.
Treatment of hypercalcemia
Severe elevations of calcium may be treated with intravenous saline followed by furosemide and, if changes persist, with glucocorticoids and calcitonin. Bisphosphonates are also increasingly used in this situation (eg, oral etidronate or intravenous pamidronate). Treatment of subcutaneous fat necrosis is with low-calcium formulas; fluid, furosemide, calcitonin, and glucocorticoids are used as indicated depending on the degree of hypercalcemia. Fetal hypercalcemia due to maternal hypoparathyroidism may be managed expectantly, as it usually resolves spontaneously within a few weeks. Treatment of chronic conditions includes low-calcium and vitamin D formulas.