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Methylmalonic Acid Blood Test

Last updated July 15, 2019

Approved by: Maulik P. Purohit MD MPH

Jan Friml

A Methylmalonic Acid (MMA) Blood Test is a test that assesses the levels of MMA in blood. It is used to indirectly detect vitamin B12 deficiency. It is also used to diagnose a rare genetic disease, called methylmalonic acidemia.


What are other Names for this Test? (Equivalent Terms)

  • MMA Blood Test

What is Methylmalonic Acid Blood Test? (Background Information)

  • Methylmalonic acid (MMA) is a precursor to a necessary component of the Krebs cycle. The Krebs cycle is a crucial metabolic pathway, which is utilized by virtually every cell in the body
  • Through a series of enzymatic reactions, MMA is converted to succinyl-CoA; this succinyl-CoA then enters the Krebs cycle. The Krebs cycle is an important pathway with two purposes - energy production and the synthesis of important molecules required by the body
  • The conversion of MMA to succinyl-CoA requires vitamin B12 (also known as cobalamin). Insufficient levels of vitamin B12 slow down the enzymatic conversion. With less MMA being converted to succinyl-CoA, the levels of MMA quickly build-up
  • While MMA accumulates, less succinyl-CoA is available to enter the Krebs cycle. Thus, the cells’ ability to produce energy and important molecules is affected
  • A Methylmalonic Acid (MMA) Blood Test is a test that assesses the levels of MMA in blood. It is used to indirectly detect vitamin B12 deficiency. It is also used to diagnose a rare genetic disease, called methylmalonic acidemia

What are the Clinical Indications for performing the Methylmalonic Acid Blood Test?

The following are certain clinical indicators for performing a Methylmalonic Acid Blood Test:

  • Anemia
  • Fatigue
  • Persistent bleeding
  • Memory loss
  • Tingling sensation in the extremities
  • Vomiting
  • Enlarged liver
  • Failure of an infant to thrive

How is the Specimen Collected for Methylmalonic Acid Blood Test?

Following is the specimen collection process for Methylmalonic Acid Blood Test:

Sample required: Blood

Process: Insertion of a needle into an arm vein.

Preparation required: No special preparation is needed prior to the test.

What is the Significance of the Methylmalonic Acid Blood Test Result?

Increased methylmalonic acid levels may indicate:

  • Vitamin B12 deficiency
  • Methylmalonic acidemia

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

  • The Methylmalonic Acid Blood Test is a very sensitive test. Nevertheless, one in 4 cases of increased MMA levels is not worrisome
  • The methylmalonic acid levels increase with age
  • With rare exceptions, vitamin B12 is available only from animal sources. Individuals with vegan diets are at an increased risk for vitamin B12 deficiency; they must supplement their diets with foods containing adequate amounts of vitamin B12

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.

References and Information Sources used for the Article:


Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: June 8, 2014
Last updated: July 15, 2019