Calcium4hurmcnc
This test measures the amount of calcium in your urine collected over a 4-hour period to help evaluate calcium metabolism and diagnose related conditions.
{"Measures calcium levels in urine collected over 4 hours","Helps diagnose kidney stones, bone disorders, and calcium metabolism problems","Requires collecting all urine during the 4-hour period","Results may be affected by diet, medications, and kidney function"}
Key facts at a glance
- LOINC
- 12511-2
- Short code
- U_CA_4HR
- Synonyms
- Calcium 4h Ur-mCnc
- Category
- electrolyte
- Sample
- urine
- Container
- Clean sterile plastic urine container (60-100 mL capacity for aliquot)
- Units
- not specified
- Ref low
- 1
- Ref high
- 20
- Critical range
- 50 not specified – 400 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Spectrophotometry (Arsenazo III method) or Atomic Absorption Spectroscopy (AAS)
- CPT
- 82340
- SNOMED
- 314889006
- Specimen volume
- Submit 10 mL aliquot from well-mixed 4-hour collection; record total collection volume
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 72 hours; Frozen (-20°C): 30 days
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
The 4-hour urine calcium test measures how much calcium your kidneys are excreting in your urine over a 4-hour period. Calcium is an essential mineral for strong bones, muscle function, and nerve signaling. This test helps doctors understand how your body processes calcium and whether your kidneys are working properly.
How is the test performed?
You will be given a special container to collect all your urine for exactly 4 hours. It's important to collect every drop during this period, including the first morning urine. The collected sample is then sent to a laboratory where technicians measure the calcium content. Your doctor may ask you to follow specific dietary instructions before the test.
What do the results mean?
High urine calcium levels (hypercalciuria) may indicate kidney stones, hyperparathyroidism, or certain bone diseases. Low urine calcium levels (hypocalciuria) may be seen in vitamin D deficiency, kidney disease, or certain genetic conditions. Your doctor will interpret your results based on your symptoms and other test findings.
Reference range
1.0-20.0 mg/dLnot specified
Complete timed 4-hour urine collection (often after overnight fast per protocol); avoid calcium supplements/dairy if specified
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?
What medications can affect the test results?
Is the test painful?
How long does it take to get results?
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