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Methylmalonic Acid (MMA), Urine or Blood

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

Measures methylmalonic acid in urine or blood to help evaluate vitamin B12 metabolism and related metabolic disorders.

Quick summary

["Elevated MMA may suggest vitamin B12 deficiency, although kidney disease and other conditions can also raise it."]

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

Key facts at a glance

LOINC
105151-5
Short code
MRA UE ves-Bl
Synonyms
MRA UE ves-Bl
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr-angio
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test measures methylmalonic acid (MMA), a substance involved in breaking down certain fats and amino acids. Your healthcare professional may order it using a blood or urine specimen.

Why might I need this test?

MMA is often checked when vitamin B12 deficiency is suspected, particularly if symptoms such as numbness, tingling, balance problems, or unusual fatigue are present. It may also be used when evaluating inherited metabolic conditions.

How is the test performed?

For a blood test, a healthcare professional draws blood from a vein. For a urine test, you usually collect urine in a sterile container as instructed by the laboratory. The specimen is then measured to determine the amount of MMA present.

How do I prepare for the test?

Fasting is generally not required, but follow the instructions provided by your healthcare professional or laboratory. If a timed urine collection is requested, collect all urine for the specified period and record the start and end times.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

MMA test

Frequently asked questions

Does an abnormal MMA result always mean I have vitamin B12 deficiency?
No. Elevated MMA can have several causes, including kidney disease and medication effects, so your healthcare professional will interpret it alongside your medical history and other tests.
Is fasting required for an MMA test?
Fasting is usually not required, but laboratory instructions should take priority. Some tests that evaluate vitamin B12 status may include additional fasting or timing requirements.
Which specimen is better for measuring MMA?
Either blood or urine can be used depending on the test ordered and the laboratory's method. Your healthcare professional or laboratory will tell you which specimen to provide.
  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