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Methylmalonic Acid (MMA) in Serum or Plasma

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

This test measures the amount of methylmalonic acid, a breakdown product of certain amino acids, in your blood. It helps assess how well your body is processing nutrients and can indicate vitamin deficiencies or metabolic disorders.

Quick summary

["MMA levels may signal vitamin B12 or folate deficiencies or metabolic issues."]

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

Key facts at a glance

LOINC
36795-3
Short code
MRA LE ves-L
Synonyms
MRA LE ves-L
Category
chemistry
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

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like fatigue, weakness, nerve problems, or unexplained anemia. It’s also used to monitor conditions like pernicious anemia, vitamin B12 deficiency, or metabolic disorders like methylmalonic aciduria.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the draw if your test involves fasting. Bring any medications or supplements you’re taking to your appointment.

How the Test Works

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it’s analyzed to measure MMA levels using a specialized method, often an immunoassay or enzymatic technique.

What the Results Mean

High MMA levels may suggest vitamin B12 or folate deficiency, certain genetic metabolic disorders, or conditions affecting nutrient absorption. Low levels are less common but could indicate overproduction of MMA in rare metabolic diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated MMA is strongly linked to vitamin B12 deficiency, especially in people with pernicious anemia or malabsorption issues. It can also signal inherited metabolic disorders like methylmalonic aciduria, which require early diagnosis for treatment. Low levels are less frequently associated with clinical concerns but may warrant further investigation in specific cases.

Short name

MMA Level

Frequently asked questions

What causes elevated MMA levels?
Elevated MMA can result from vitamin B12 or folate deficiency, certain medications (like proton pump inhibitors), or metabolic disorders. Rarely, it may appear in people with kidney disease or genetic conditions affecting amino acid metabolism.
How is MMA treated?
Treatment depends on the underlying cause. Vitamin B12 deficiency is typically treated with injections or high-dose supplements. If a metabolic disorder is suspected, a specialist may recommend dietary changes, enzyme therapy, or other targeted treatments.
Can MMA levels change with diet?
Yes, diet can influence MMA levels. A balanced diet rich in vitamin B12 and folate may help normalize levels, but severe deficiencies often require medical intervention. Avoiding certain medications (like antacids) that interfere with nutrient absorption can also help.
  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