Generality
Calciuria is a laboratory index that measures the amount of calcium filtered by the kidneys and excreted in the urine.
This test allows the screening, diagnosis and monitoring of various conditions associated with alterations in calcium metabolism (including malnutrition, thyroid and intestinal diseases, some cancers and nephropathies). Therefore, the dosage of calcium in the urine completes the picture provided by the calcemia (concentration of calcium in the blood).
What's this
Calciuria is a laboratory test that evaluates the concentration of calcium in the urine. It is a "complementary investigation, useful for investigating the metabolism of calcium in the body," which mainly involves three hormones: calcitonin, parathyroid hormone and calcitriol (activated vitamin D).
Because it is measured
The determination of calcium can be performed to check for any dysfunction of the parathyroid glands and to understand if the kidney stones are the consequence of an "excessive concentration of calcium in the urine."
The dosage of the mineral is performed by collecting the urine for 24 hours, taking care to check the dietary intake of calcium in the 2-3 days preceding the examination (for example 1,000 mg per day).
Along with calcium urination, a test to evaluate creatinine clearance, a very important index of kidney function, and a test to measure parathyroid hormone levels may be done.
