Calcium in Urine Test

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 aren't normal, it may be a sign of kidney disease, a parathyroid disorder, bone disease, or another condition that affects how your body uses calcium.

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. If there's too much calcium in your blood, the extra calcium may be stored in your bones or passed in your urine and stool (poop).

Having just the right amount of calcium in your blood is necessary for your nerves, muscles, and heart to work properly. Your blood calcium levels are carefully controlled by your parathyroid glands, which are 4 pea-sized glands in your neck. If your blood calcium levels get too low, these glands make parathyroid hormones (PTH). The hormones are chemical messengers in your bloodstream that work to increase your blood calcium levels until they are normal again.

PTH raises blood calcium levels by:

• Causing your bones to release calcium into your blood
• Helping your intestines absorb calcium from food
• Helping your kidneys hold on to calcium and return it to your blood instead of flushing it out in urine

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

What is it used for?

A calcium in urine test may be used with other tests to help:

• Diagnose kidney stones if you have symptoms. Kidney stones form when you have high levels of certain minerals in your urine. Most kidney stones are made of calcium. So, a calcium in urine test helps your health care provider figure out if a kidney stone could be causing your symptoms and whether it's likely made of calcium. This information also helps decide what treatment you may need to prevent future stones.
• Diagnose or monitor problems with how well your kidneys are working.
• Learn more about how your parathyroid glands are working if you:
  • Have symptoms of underactive parathyroid glands
  • Have been diagnosed with overactive parathyroid glands
• Learn more about the cause of a bone disease you have, such as osteoporosis.
• Learn more about the cause of abnormal results on a calcium blood test.

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 been diagnosed with overactive parathyroid glands (hyperparathyroidism). This means your glands make too much parathyroid hormone (PTH). The test can help find out how severe your condition is. It can also help show if a kidney problem may be causing high PTH.
• You have symptoms of underactive parathyroid glands (hypoparathyroidism). This means your glands make too little PTH. Without enough PTH, your kidneys may filter too much calcium out of your blood and into your urine. Symptoms of hypoparathyroidism include:
  • Tingling fingers and toes
  • Muscle cramps and spasms in the face, hands, legs, and feet
  • Muscle weakness and fatigue
  • Seizures

Your provider may also order a calcium in urine test if you had a routine calcium blood test with abnormal results.

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?

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

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 many conditions, including:

• A kidney stone
• Overactive parathyroid glands (hyperparathyroidism)
• Certain types of cancer, including cancer that spreads to the bones
• Bone disorders, including Paget's disease of bone and osteoporosis
• Sarcoidosis

Lower than normal calcium levels in urine may be a sign of many conditions, including:

• Kidney disease
• Underactive parathyroid glands (hypoparathyroidism)
• 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. Urine calcium levels can be affected by:

• Your diet, for example, eating foods with a lot of sodium (salt)
• Certain supplements, such as taking too much vitamin D for a long period of time
• Certain medicines, including antacids and some diuretics (water pills)

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 calcium and other minerals in your bones.