Methylmalonic acid (serum)

Alternative names, keywords

MMA

Samples required

● Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

Test indications

Suspected B₁₂ deficiency.

MMA requests will only be routinely referred if B₁₂ is in the indeterminate range between the lower limit of the laboratory's reference range (197 ng/L) and the 350 ng/L cut-off given in NICE guideline NG239, Vitamin B12 deficiency in over 16s: diagnosis and management
Published: 06 March 2024.

Reference range

< 0.29 µmol/L   considered NOT indicative of B12 deficiency

0.29 - 0.70 µmol/L   suggests B12 deficiency

> 0.70 µmol/L   consistent with overt B12 deficiency

Nitrous oxide exposure can cause a functional B12 deficiency.
Elevated serum methylmalonate can also occur with renal impairment and in inherited cobalamin metabolism disorders. 

Turnaround time

Referral lab quotes turnaround time of 10 days, however additional time must be allowed for packing, dispatch and delivery of sample, and return and processing of results.

Enquiries

Biochemistry (Referrals)