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###1: Calcium [Mass/time] in 24-Hour Urine

Published: August 9, 2026Updated: August 16, 2026

###3: This test measures the total amount of calcium excreted in urine over 24 hours. It can help evaluate calcium balance and identify unusually high urinary calcium excretion.

Quick summary

["###4: The result shows how much calcium your body loses in urine over one day and can help assess kidney-stone risk and calcium metabolism."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
27055-3
Short code
FCA 24h Ur-mRate
Synonyms
FCA 24h Ur-mRate
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

###5: What This Test Measures

###6: A 24-hour urine collection is used to measure total calcium excretion. The result may be evaluated alone or with blood calcium, creatinine, kidney-function tests, and other studies.

###7: How the Test Is Collected

###8: Urine is usually collected for exactly 24 hours, beginning after an initial bladder emptying and ending with a final collection. Follow the laboratory’s timing and storage instructions carefully because an incomplete collection can affect the result.

###9: Why the Test May Be Ordered

###10: Clinicians may order this test for recurrent calcium kidney stones, suspected hypercalciuria, or evaluation of conditions that alter calcium balance, including parathyroid and kidney disorders.

###11: Factors That Can Affect the Result

###11: Dietary calcium, hydration, vitamin D supplements, calcium-containing antacids, and medications such as diuretics can change urinary calcium. Inform your clinician about these factors and do not change your diet or medications unless instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

###2: 24-Hour Urine Calcium

Frequently asked questions

###14: Why would a clinician order a 24-hour urine calcium test?
###15: It is commonly used to evaluate recurrent kidney stones, suspected high urinary calcium excretion, and disorders affecting calcium or parathyroid function.
###16: Does this test alone diagnose hyperparathyroidism?
###17: No. Urinary calcium can support the evaluation, but hyperparathyroidism generally requires blood calcium and parathyroid hormone testing and clinical assessment.
###18: How can I improve the accuracy of the collection?
###19: Collect all urine for the full period specified by the laboratory, record the start and finish times, and follow any refrigeration or dietary instructions. Tell the clinician about calcium or vitamin D supplements and prescription medications.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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