Test guide

Methylmalonic Acid (MMA) Test

This test measures the amount of methylmalonic acid (MMA) in your blood or urine. MMA is a substance made in small amounts when you digest protein. MMA is needed for metabolism, which is the process that your body uses to change food into energy.

For everyone & professionalsReviewed 2026-10-18

What it is for

An MMA test is most often used to diagnose a vitamin B12 deficiency. The test is usually also included as part of a series of tests called a newborn screening . A newborn screening checks for a variety of health conditions. An MMA test checks for methylmalonic acidemia , a rare genetic disorder . Symptoms of this disorder can range from mild to severe and may include: Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.

Limitations

Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.

Also known as

  • MMA

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