Calcium2hurmcnc
A laboratory test that measures the amount of calcium in a 2-hour urine collection to evaluate calcium metabolism and related conditions.
{"Measures calcium levels in urine collected over 2 hours","Helps diagnose kidney stones and bone disorders","May require specific dietary preparation before the test","High levels may indicate hyperparathyroidism or excessive vitamin D","Low levels may suggest kidney problems or vitamin D deficiency"}
Key facts at a glance
- LOINC
- 57334-5
- Short code
- CAU2H
- Synonyms
- Calcium 2h Ur-mCnc
- Category
- electrolyte
- Sample
- urine
- Container
- Clean plastic urine container (sterile, no preservatives)
- Units
- not specified
- Ref low
- 1
- Ref high
- 40
- Critical range
- 6 not specified – 14 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Atomic Absorption Spectrophotometry (AAS) or Colorimetric (o-Cresolphthalein Complexone method)
- CPT
- 82310
- SNOMED
- 271563006
- Specimen volume
- Minimum 10 mL; entire 2-hour collection preferred
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 2-hour urine calcium test measures the amount of calcium excreted in your urine over a 2-hour period. Calcium is an essential mineral that plays a crucial role in bone health, muscle function, nerve transmission, and blood clotting. Normally, the kidneys filter calcium from the blood, and some of it is reabsorbed back into the body while the excess is excreted in urine.
How is the test performed?
Before the test, your healthcare provider may ask you to follow specific instructions, such as fasting overnight or maintaining a normal calcium diet. You will collect all urine produced during a 2-hour period into a special container provided by the laboratory. It's important to collect the entire sample accurately and keep it refrigerated or on ice if instructed. After collection, the sample is sent to a laboratory where the calcium concentration is measured.
What do the results mean?
Normal urine calcium levels typically range from 100 to 300 mg per 24 hours (or proportionally less in a 2-hour sample). However, reference ranges may vary depending on the laboratory. Your healthcare provider will interpret your results based on your overall health, diet, and other test findings.
Reference range
1-40 mg/dL (lab-specific; highly variable)not specified
Overnight fast preferred; discard first morning void then collect timed 2-hour urine while continuing fast (water only); avoid calcium supplements
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before the test?
Is the test painful?
How long does it take to get results?
What should I do if my results are abnormal?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy