Also known as: calcium deficiency disease.

What is hypocalcemia?

If a person doesn’t have enough calcium circulating in the blood, a not uncommon condition, it is known as hypocalcemia. Calcium has many important roles in the body, including the bones where 90% of body calcium is found, the nervous system, for smooth muscle function, and in many important cellular activities. Blood calcium level is regulated by an endocrine gland that lies in the thyroid gland called the parathyroid, which secretes a hormone called parathormone or PTH, vitamin D, liver and kidney metabolic functions, serum phosphate and magnesium levels.

Hypocalcemia is a laboratory and clinical abnormality and is seen in the premature, full term newborn baby, and in children where blood level definitions of hypocalcemia are different for each group.

What causes hypocalcemia?

In the first 48-72 hours of life hypocalcemia is commonly seen in preterm and very low birth weight babies though many times for unknown reasons. Most common in those who are asphyxiated or neurologically depressed at birth, infants of diabetic mothers, and those infants who haven’t grown normally during intrauterine life.

After 3-7 days of life and during the first month, known as late neonatal, hypocalcemia is commonly associated with cow’s milk feedings, vitamin D deficiency and a low magnesium blood level. Other causes include immunodeficiency disorders, gentamicin administration, transient low activity of the parathyroid gland, maternal increased parathyroid activity, blood transfusions and phototherapy for jaundice in the newborn period.

In infants and children, hypocalcemia can result from kidney failure, small/absent or damaged parathyroid glands, cells not responding to parathormone (pseudoparathyroidism), gene abnormalities and unknown or idiopathic causes. In addition, abnormal vitamin D production or action, and high levels of blood phosphate levels are not uncommon causes of a low blood calcium level.

In infants and children other causes include bowel malabsorption syndromes, changes in the acidity of the blood, and inflammation of the pancreatic gland (pancreatitis).

What are the symptoms of hypocalcemia?

In the newborn, there may be no symptoms or they may present with poor feeding, lethargy, vomiting, abdominal dissension, jitteriness, seizures and episodes of not breathing (apnea).

In children, there may be lethargy, “tetany” which is a sign of nerve irritability like spasms of hands or feet, a bluish color to lips, tongue and nails (cyanosis), cramping, twitching or tremulousness, seizures, tingling sensation in the extremities, mood changes, and trouble speaking or swallowing.

What are hypocalcemia care options? 

Asymptomatic patients may be treated with oral calcium whereas it is given intravenously to infants/children who have symptomatic. Magnesium and phosphate lowering agents may be required. A special diet and replacement therapy with recombinant PTH are frequent treatment approaches.

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: July 25, 2022 02:45 PM

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