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Total Calcium/Creatinine Ratio, Urine

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

Measures urine calcium relative to urine creatinine, helping assess calcium excretion while accounting for urine concentration.

Quick summary

["This urine test helps identify abnormal calcium loss when interpreted with your other results."]

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

Key facts at a glance

LOINC
56646-3
Short code
TCA/Creat Ur-Rto
Synonyms
TCA/Creat Ur-Rto
Category
kidney
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

What is this test?

This test measures the amount of calcium in urine relative to the amount of creatinine. Creatinine is a waste product used to help account for how concentrated the urine sample is.

Why might I need this test?

Your clinician may use this test to evaluate increased calcium loss in the urine, investigate kidney stones, or assess calcium metabolism when blood calcium results are unclear.

How is the test performed?

A urine sample is tested to determine its calcium and creatinine concentrations. The laboratory then calculates the calcium-to-creatinine ratio. Depending on the order, this may be measured in a single urine sample or from a timed collection.

How do I prepare for the test?

Follow your clinician's collection instructions exactly. If a 24-hour collection is requested, collect all urine for the specified period and record the start and end times. Your clinician will advise whether to adjust calcium or vitamin D intake before testing.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine calcium/creatinine ratio

Frequently asked questions

Is this the same as a 24-hour urine calcium test?
Not necessarily. A calcium-to-creatinine ratio can be calculated from a single urine sample, while a 24-hour urine calcium test measures the total calcium excreted over a full day. Check the collection instructions provided with your order.
Why is creatinine included?
Urine concentration varies throughout the day. Creatinine provides a reference that helps normalize the calcium measurement to account for urine concentration.
What can affect the result?
Dietary calcium, vitamin D supplements, hydration, kidney function, and certain medicines can affect urine calcium. Tell your clinician about relevant supplements, medications, and medical conditions.
  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