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Low Calcium in Babies (Hypocalcemia)

Medically reviewed by: Melanie L. Pitone, MD

What Is Hypocalcemia?

Hypocalcemia (hye-poe-kal-SEE-mee-uh) is when the level of calcium in the blood is too low. Calcium is a mineral that the body needs to build healthy bones and teeth. It also helps nerves, muscles, and the heart work well. A baby with low calcium can become very sick and also have problems with bones and nerves later if the condition isn't treated.

What Are the Signs & Symptoms of Hypocalcemia in Babies?

Symptoms of hypocalcemia depend on how low the baby's calcium is and how fast the drop happened.

A baby with hypocalcemia might:

  • be fussy
  • vomit
  • seem weak or floppy
  • twitch, shake, or seem jittery
  • not feed well
  • be sluggish
  • have seizures

Some babies with hypocalcemia may have signs of rickets, a softening of the bones.

What Causes Hypocalcemia in Babies?

Calcium in the blood can get too low if:

  • The baby's diet is low in calcium. This can happen if a baby is fed homemade formula or watered-down formula. It also can happen if babies younger than 1 year old drink cow's milk, goat's milk, or other types of milk. Breast milk and store-bought infant formula are the safest for babies. They have the right amounts of calcium and other minerals babies need.
  • The baby's diet is too low in vitamin D. Vitamin D, which helps the body absorb calcium, is in store-bought infant formula. Babies fed only breast milk need vitamin D supplements.
  • A hormone (chemical in the body) that controls the amount of calcium in the blood is too low.

Rarely, newborns also can have neonatal hypocalcemia, a health problem that causes calcium to be out of balance.

Hypocalcemia is more common in babies than in older kids. Infants born early or born very small, who had a difficult birth, or are born to a mom with diabetes are most at risk for it.

How Is Hypocalcemia Diagnosed?

Doctors diagnose hypocalcemia by asking questions, checking the baby, and doing blood tests.

How Is Hypocalcemia Treated?

Babies with hypocalcemia symptoms will get calcium through an IV to bring their level back to normal. They'll get this in the hospital, often while in the ICU. Doctors also look for the cause of the low calcium and work to treat that.

Some babies without symptoms might have mild hypocalcemia that's found when lab tests are done for other reasons. This can clear up on its own when the babies get nutrition with the right amount of calcium and other minerals. Sometimes doctors might give calcium or vitamin D as a medicine the baby can swallow.