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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Vitamins

Methylmalonic Acid (MMA) (Blood)

MMA Blood measures a functional B12 marker that may be particularly informative for older adults. As B12 absorption and metabolism may change with age, MMA testing could reveal deficiencies not detected by standard B12 blood tests.

Reference Ranges

Male
Low 0 Normal 0.4 High
Female
Low 0 Normal 0.4 High

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

What It Measures

This test measures methylmalonic acid in your blood, a metabolite that accumulates when vitamin B12 is insufficient for normal metabolic reactions. MMA is considered a sensitive functional marker because it reflects actual B12 activity within your cells.

Why It Matters

Older adults may have normal B12 blood levels but still experience functional deficiency at the cellular level. Elevated MMA could indicate that B12 supplementation or treatment adjustment is needed to support cognitive function and nerve health.

When to Test

Testing may be recommended when B12 deficiency is suspected but standard tests are inconclusive, when you have symptoms suggesting B12 deficiency with normal B12 levels, or to monitor the effectiveness of B12 treatment. Consult your healthcare provider.

Symptoms

Low Levels

Low MMA levels are generally considered normal and desirable, indicating adequate vitamin B12 function at the cellular level. This typically means your body has sufficient B12 to support its metabolic processes.

High Levels

Some people with elevated MMA levels may experience fatigue, weakness, tingling or numbness in extremities, cognitive difficulties, and balance problems. These symptoms may indicate functional B12 deficiency that should be evaluated by a healthcare provider.

Lifestyle Tips

If MMA levels are elevated, increasing B12 intake through diet or supplementation may be recommended by your healthcare provider. Regular monitoring can help track whether interventions are effectively lowering MMA back to normal levels.

Frequently Asked Questions

Why test MMA if I already tested B12?
MMA is a functional marker that reflects how B12 is being used at the cellular level. You can have seemingly normal B12 blood levels while still experiencing functional deficiency. MMA testing may reveal this hidden insufficiency.
Can kidney function affect MMA results?
Yes, reduced kidney function can cause MMA levels to rise independently of B12 status, since the kidneys are involved in clearing MMA from the blood. Your healthcare provider should consider kidney function when interpreting MMA results.
How quickly do MMA levels respond to B12 treatment?
MMA levels typically begin to decrease within days to weeks of adequate B12 supplementation. Your healthcare provider may recommend retesting after a period of treatment to confirm that levels are normalising.