Methylmalonic Acid (MMA) Test
Reviewed
This test measures the amount of methylmalonic acid (MMA) in your blood or urine. High MMA levels can be a sign of a vitamin B12 deficiency. The test is also used in newborn screening to check for methylmalonic acidemia, a rare genetic disorder.
Preparation and collection
You may need to fast (not eat or drink) for several hours before the test. Follow any special instructions from your provider.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- The test cannot show how much of a deficiency you have.
- Results must be interpreted together with your symptoms, medical history, and other tests (such as homocysteine and vitamin B tests).
What to do next
If you have questions about your results, talk to your provider. For a baby diagnosed with methylmalonic acidemia, discuss treatment options with the child's provider.
Evidence source
U.S. National Library of Medicine: Methylmalonic Acid (MMA) Test