Calcium in Urine Test
Reviewed
Also called: urinalysis (calcium), urinary Ca+2
A calcium in urine test measures the amount of calcium in your urine. 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.
Specimen: urine (24-hour collection)
Why this test may be ordered
- Diagnose kidney stones if you have symptoms
- 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 or 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
Preparation and collection
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.
You'll need to collect all your urine during a 24-hour period (24-hour urine sample test). You will be given a special container and instructions. Begin by urinating in the toilet as usual (do not collect this urine) and note the time. For the next 24 hours, collect all urine in the container and store it in a refrigerator or cooler with ice. After 24 hours, urinate if possible as the last collection. Return the container as instructed.
There is no known risk to having a calcium in urine test.
Understanding results
Your results will show whether your urine calcium level is higher or lower than normal. However, normal ranges may vary by laboratory. Your healthcare provider will interpret your results based on your individual health situation.
- Higher than normal: May indicate a kidney stone, overactive parathyroid glands (hyperparathyroidism), certain types of cancer including cancer that spreads to bones, bone disorders such as Paget's disease or osteoporosis, or sarcoidosis. Limitation: Results can be affected by your diet (e.g., high sodium intake), certain supplements (e.g., too much vitamin D), and certain medicines (e.g., antacids, diuretics). An abnormal result does not always mean a medical condition that needs treatment. Next step: Consult your healthcare provider to interpret your result and determine if further testing is needed.
- Lower than normal: May indicate kidney disease, underactive parathyroid glands (hypoparathyroidism), too little vitamin D or magnesium, malabsorption disorder, or malnutrition. Limitation: Results can be affected by your diet, supplements, and medicines. An abnormal result does not always mean a medical condition that needs treatment. Next step: Consult your healthcare provider to interpret your result and determine if further testing is needed.
- A calcium in urine test does not tell you how much calcium is in your bones; bone health is measured with a DEXA scan.
- Urine calcium levels can be affected by diet, supplements, and medicines, which may lead to false interpretation if not accounted for.
What to do next
Talk with your healthcare provider about your results. They may recommend additional tests such as blood calcium tests, parathyroid hormone tests, or imaging to determine the cause of abnormal levels and guide treatment.
- Why do I need to collect urine for 24 hours instead of a single sample?
- How should I store the urine collection container during the test period?
- Can my diet affect my urine calcium levels?
- What should I do if I miss a urine collection during the 24-hour period?