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Methylmalonate-to-Creatinine Ratio, Urine

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

A urine test that measures methylmalonate relative to creatinine, often used to help evaluate possible vitamin B12 deficiency.

Quick summary

["An elevated result may support vitamin B12 deficiency, but kidney function and other factors must also be considered."]

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

Key facts at a glance

LOINC
13776-0
Short code
Methylmalonate/Creat Ur
Synonyms
Methylmalonate/Creat Ur
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 methylmalonate, a substance related to vitamin B12 metabolism, in urine. Dividing it by urine creatinine helps account for differences in urine concentration.

Why might I need this test?

Your clinician may order it when symptoms or blood test findings suggest that vitamin B12 deficiency is possible. It can be used with other tests, such as vitamin B12 and homocysteine measurements, to help clarify the diagnosis.

How is the test performed?

A urine sample is collected and analyzed in the laboratory to measure methylmalonate and creatinine. The results are reported as a ratio, so the amount of methylmalonate is adjusted for the concentration of the urine sample.

How do I prepare for the test?

Follow your clinician's or laboratory's urine collection instructions exactly. The test may be performed on a random urine sample or a first-morning sample, and you may be asked to avoid certain supplements before collection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Methylmalonate/Creatinine Ratio

Frequently asked questions

Does an elevated result definitely mean I have vitamin B12 deficiency?
No. It may support vitamin B12 deficiency, but kidney disease and other factors can also raise the result. Your clinician will interpret it alongside other tests.
Why is creatinine included in this urine test?
Creatinine is used to adjust the methylmalonate measurement for how concentrated or dilute the urine is. This helps make results from different urine samples more comparable.
Should I stop taking vitamin supplements before the test?
Do not stop prescribed supplements without medical advice. Ask your clinician or laboratory whether biotin or other supplements could affect the result or need to be held before collection.
  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