MMA - Methylmalonic Acid

General Information

Methylmalonic acid (MMA) is a small molecule produced in the body that is necessary for metabolism and energy production.  The conversion of a form of MMA, methylmalonyl coenzyme A, to succinyl coenzyme A requires the cofactor, vitamin B12.  MMA has no known biological function.  

Increased MMA in serum can be due to a lack of vitamin B12, a primary metabolic defect, renal insufficiency or hypovolaemia.  Decreased MMA levels are uncommon and are not considered to be clinically significant.

Measuring MMA can aid detection of early vitamin B12 deficiency.  It is more specific than homocysteine as a marker for B12 deficiency as, unlike MMA, homocysteine is also affected by folate status.  The timely detection, and correction, of vitamin B12 deficiency prevents macrocytic anaemia, elevated homocysteine (possible thrombotic risk factor), potentially irreversible peripheral neuropathy, memory loss and other cognitive deficits.