What Methylmalonic acid measures
Methylmalonic acid rises when cellular B12-dependent reactions are not running efficiently. It is often more useful than serum B12 alone when the question is functional sufficiency.
Why this marker matters
When TCN2 or methylation-related pathways are relevant, methylmalonic acid helps separate true B12-related issues from more generic fatigue or cognition complaints.
When to check it
- when B12 looks borderline or confusing
- when low energy or brain fog persists despite supplementation
- when DNA points toward nutrient transport or methylation pressure
How to interpret it
- use it with B12, homocysteine, and symptom context
- functional markers usually outperform serum B12 alone
- do not interpret isolated values without the broader pathway picture
Where it fits in DNA follow-up
This marker is most useful when nutrient transport and methylation support hypotheses overlap.
Example interpretation
Your nutrient-transport pathway may deserve closer follow-up because methylmalonic acid can show whether B12 support is functionally adequate.
Suggested companion markers: homocysteine and holotranscobalamin.