Hypercalcemia and Hypercalciuria

People with Williams syndrome (WS) may have hypercalcemia (high calcium levels in the blood) or hypercalciuria (high levels of calcium in the urine). High calcium levels in the blood are more common in infancy, but could occur any time in life.


Symptoms of hypercalcinemia include:

  • In babies, irritability, vomiting or constipation. These symptoms can also be caused by other medical conditions.
  • In older children, symptoms can include abdominal (belly area) pains, fatigue or frequent urination

Symptoms of hypercalcinuria include:

  • There are usually no symptoms of hypercalciuria. Doctors can usually diagnose hypercalciuria through a urine test.
  • Over time, the build-up of calcium can lead to a condition called nephrocalcinosis. This is not the same as having kidney stones. It usually will be followed by a nephrologist (doctor who specializes in the kidneys).

What Are Treatment Options for Hypercalcinuria and Hypercalcinemia?

  • Regular blood and urine tests
  • A diet that is low in calcium. This means no more than 3 servings of dairy or calcium-fortified foods (foods with calcium added) per day. If you would like to give your child a multivitamin with calcium, please ask the care team for recommendations. Your child will need regular blood tests throughout their life to check their calcium levels and bone density (the amount of material in the bones).
  • In rare cases, your child might need more medical care for issues caused by hypercalcinemia. This usually happens if your baby is not feeding well or gets sick. After treatment, calcium levels usually return to normal.
  • In some cases, your child might need a renal ultrasound (kidney ultrasound). This helps make sure calcium is not collecting in the kidneys.

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Rev. 8/2019. Mass General for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This handout is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.