Description
Why It’s Done
The test is commonly used to:
1. Diagnose or Monitor Medical Conditions
• Hypercalciuria (excess calcium in urine)
• Kidney stones (calcium stones)
• Parathyroid gland disorders (e.g., hyperparathyroidism)
• Calcium metabolism disorders
• Paget’s disease or other bone disorders
2. Evaluate Kidney Function
• To determine how well the kidneys are excreting calcium
• To help in the evaluation of renal calcium loss or calcium retention
3. Monitor Therapy
• For patients taking calcium or vitamin D supplements
• For individuals with a history of recurrent kidney stones
Preparation
1. 24-Hour Urine Collection
• You will need to collect all urine over a 24-hour period.
• Discard the first urine of the day and then collect all urine for the next 24 hours, including the first urine of the next morning.
• Use the container provided by the lab, which may contain a preservative.
• Keep the container refrigerated or in a cool place during the collection period.
• Do not miss any samples, as it could affect the accuracy of the test.
2. Diet and Medications
• Avoid high-calcium foods or supplements 24–48 hours before and during the collection if instructed by your doctor.
• Inform your doctor about all medications and supplements you are taking. Some that may affect the test include:
o Diuretics
o Calcium or vitamin D supplements
o Antacids
o Steroids
o Thiazide medications
Do not stop any medication unless directed by your healthcare provider.
3. Hydration
• Stay well hydrated, but avoid excessive fluid intake, which can dilute the sample
