Calcium Urine Test in California

What this test measures

Calcium balance depends on the interplay between the bones, kidneys, parathyroid glands, and vitamin D. The kidneys filter calcium and reabsorb much of it, and the amount that appears in urine reflects how much the body is excreting. A urine calcium measurement can reveal patterns that a blood test alone would not show, particularly when the concern involves stone formation or hormone regulation.

The test is usually performed on a timed urine collection, such as a twenty-four-hour sample, although some orders use a shorter collection. The laboratory measures the total calcium in the sample and may also report related values such as urine creatinine to confirm that the collection was complete. Correct collection timing is important for an accurate result.

Clinicians order a urine calcium test to investigate recurrent kidney stones, to evaluate suspected parathyroid disorders, or to monitor conditions and treatments that affect calcium handling. It may also be used when blood calcium is abnormal and the cause is unclear. The result is interpreted with blood calcium, parathyroid hormone, and vitamin D levels.