Calcium (ca) urine test

A urine calcium test is done to:

• See whether a kidney stone has developed because of high amounts of calcium in the urine.
• See how much calcium you are getting in your diet and how well it's being absorbed by your intestines.
• Look for problems that cause your bones to lose calcium.
• See how well your kidneys are working.
• Check for problems with the parathyroid glands.

A urine calcium test is not as helpful as a blood calcium test to find certain conditions, such as hyperparathyroidism, bone diseases, or pancreatitis.

Urine calcium can be checked in a single urine sample. But it is more often measured in a 24-hour urine sample. A 24-hour urine calcium test is usually done at home.

Urine test

• You start collecting your urine in the morning. When you first get up, empty your bladder but do not save this urine. Write down the time that you urinated to mark the beginning of your 24-hour collection period.
• For the next 24 hours, collect all your urine. Your doctor or lab will usually provide you with a large container that holds about 1 gallon. The container may have a small amount of preservative in it. Urinate into a small, clean container and then pour the urine into the large container. Do not touch the inside of either container with your fingers.
• Keep the large container in the refrigerator for the 24 hours.
• Empty your bladder for the final time at or just before the end of the 24-hour period. Add this urine to the large container and record the time.
• Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in the urine sample.

• In general, you don't need to prepare before having this test. Your doctor may give you some specific instructions.
• For 24-hour urine collection, your doctor or lab will usually give you a large container that holds about 1 gallon.

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

Test results may be affected by the amount of calcium in the diet.

High values

High values of calcium in the urine may be caused by:

• Hyperparathyroidism.
• Sarcoidosis.
• Cancer.
• Paget's disease.

Low values

Low values of calcium in the urine may be caused by:

• Hypoparathyroidism.
• Not getting enough vitamin D.
• Preeclampsia.
• Kidney problems.
• Malnutrition caused by diseases such as celiac disease, pancreatitis, and alcohol use disorder.

In some cases, calcium in the urine may be low for other reasons. One example of this is idiopathic familial hypocalciuric hypercalcemia.