Methylmalonic Acid (MMA) Test Test
This test measures the amount of methylmalonic acid (MMA) in your blood or urine. High levels can indicate a vitamin B12 deficiency or, in newborns, a rare genetic disorder called methylmalonic acidemia.
What this test measures
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 and is needed for metabolism.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
Higher-than-normal levels of MMA may mean you have a vitamin B12 deficiency. In newborns, moderate or high levels may mean they have methylmalonic acidemia.
Lower-than-normal results
Lower-than-normal levels of MMA are not common and are not considered a health problem.
Frequently asked questions
What is an MMA test?
It measures the amount of methylmalonic acid (MMA) in your blood or urine. MMA is a substance made when you digest protein.
Why is this test done?
It is most often used to diagnose a vitamin B12 deficiency. It is also part of newborn screening to check for methylmalonic acidemia.
What does a high MMA level mean?
A high level may mean you have a vitamin B12 deficiency. In newborns, it may mean they have methylmalonic acidemia.
What does a low MMA level mean?
Lower-than-normal levels are not common and are not considered a health problem.
What other tests might be done with an MMA test?
Your provider may compare your results with a homocysteine blood test and/or vitamin B tests.
Related lab tests
Sources
- MedlinePlus: Methylmalonic Acid (MMA) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.