What is a Calcium in Urine Test?

A calcium in urine test measures the amount of calcium in your urine (pee). If your urine calcium levels are too high or too low, it may be a sign of kidney disease, kidney stones, bone disease, a parathyroid gland disorder, or other conditions.

Calcium is one of the most important minerals in your body. Most of your calcium is stored in your bones and teeth. About 1% of the calcium in your body is in your blood. Having the right amount of calcium in your blood is necessary for your nerves, muscles, and heart to work properly. Normally, your kidneys filter out a small amount of calcium from your blood, which leaves your body in urine.

Checking the amount of calcium in urine can help diagnose kidney problems and other conditions that can affect calcium levels in your blood. If you have symptoms of any of these conditions, your health care provider may order a calcium blood test, too.

Other names: urinalysis (calcium), urinary Ca+2

What is it used for?

A calcium in urine test may be used to diagnose or monitor how well your kidney are working. It may be used if you have symptoms of kidney stones, which are more likely to form if you have too much calcium in your urine. A calcium in urine test may also help diagnose problems with the parathyroid glands in your neck. These glands help control the amount of calcium in your body.

Why do I need a calcium in urine test?

You may need a calcium in urine test if you have symptoms of a kidney stone. These symptoms include:

• Sharp pain in your lower abdomen (belly), back, side, or groin
• Blood in your urine
• Frequent need to urinate (pee)
• Pain while urinating
• Inability to urinate or urinating only small amounts
• Cloudy or bad-smelling urine
• Nausea and vomiting

You may also need a calcium in urine test if you have symptoms of a parathyroid disorder.

Having too much parathyroid hormone doesn't always cause symptoms. When symptoms happen, they may include:

• Muscle weakness
• Fatigue
• Depression
• Bone and joint pain
• Loss of appetite
• Nausea and vomiting
• Constipation
• Confusion
• Increased thirst and urination

Symptoms of too little parathyroid hormone include:

• Abdominal (belly) pain
• Muscle cramps
• Tingling fingers and toes
• Dry skin and hair
• Brittle nails

What happens during a calcium in urine test?

You'll need to collect all your urine during a 24-hour period. This is called a 24-hour urine sample test. You will be given a special container to collect your urine and instructions on how to collect and store your samples. Your provider will tell you what time to start. The test generally includes the following steps:

• To begin, urinate in the toilet as usual. Do not collect this urine. Write down the time you urinated.
• For the next 24 hours, collect all your urine in the container.
• During the collection period, store the urine container in a refrigerator or in a cooler with ice.
• 24 hours after starting the test, try to urinate if you can. This is the last urine collection for the test.
• Return the container with your urine to your provider's office or the laboratory as instructed.

Will I need to do anything to prepare for the test?

You may be asked to avoid certain foods and medicines for several days before the test. Do not stop taking any medicines without talking with your provider. Your provider will let you know if there are any special instructions to follow.

Are there any risks to the test?

There is no known risk to having a calcium in urine test.

What do the results mean?

Higher than normal calcium levels in urine may be a sign of:

• A kidney stone
• Hyperparathyroidism (too much parathyroid hormone)
• Certain types of cancer, including cancer that spreads to the bones
• Paget's disease of bone
• Sarcoidosis
• Too much vitamin D over a long period of time, usually from supplements

Lower than normal calcium levels in urine may be a sign of:

• Hypoparathyroidism (too little parathyroid hormone)
• Kidney disease
• Hypothyroidism (too little thyroid hormone)
• Too little vitamin D or magnesium
• Malabsorption disorder
• Malnutrition

If your calcium levels aren't normal, it doesn't always mean you have a medical condition that needs treatment. Your diet and certain supplements and medicines, including antacids, can affect your urine calcium levels. If you have questions about your results, talk with your provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a calcium in urine test?

A calcium in urine test does not tell you how much calcium is in your bones. Bone health can be measured with a type of x-ray called a bone density scan, or dexa scan. A dexa scan measures the mineral content, including calcium, and other aspects of your bones.