Calcium - urine
This test measures the amount of calcium in urine. All cells need calcium in order to work. Calcium helps build strong bones and teeth. It is important for heart function, and helps with muscle contraction, nerve signaling, and blood clotting.
See also: Calcium - blood
Urinary Ca+2; Kidney stones - calcium in urine; Renal calculi - calcium in your urine; Parathyroid - calcium in urine
How the Test is Performed
A 24-hour urine sample is most often needed:
For an infant, thoroughly wash the area where urine exits the body.
This procedure may take a few tries. An active baby can move the bag, causing urine to go into the diaper. You may need extra collection bags.
Check the infant often and change the bag after the infant has urinated into it. Drain the urine from the bag into the container provided by your health care provider.
Deliver the sample to the laboratory or to your provider as soon as possible.
How to Prepare for the Test
Many medicines can interfere with blood test results.
How the Test will Feel
The test involves only normal urination, and there is no discomfort.
Why the Test is Performed
Urine calcium level can help your provider:
If you are eating a normal diet, the expected amount of calcium in the urine is 100 to 300 milligrams per day (mg/day) or 2.50 to 7.50 millimoles per 24 hours (mmol/24 hours). If you are eating a diet low in calcium, the amount of calcium in the urine will be 50 to 150 mg/day or 1.25 to 3.75 mmol/24 hours.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
A high level of urine calcium (above 300 mg/day) may be due to:
A low level of urine calcium may be due to:
Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier; 2016:chap 28.
Thakker RV. The parathyroid glands, hypercalcemia and hypocalcemia. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 245.
Review Date: 5/21/2017
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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