← Blood tests
Methylmalonic Acid (MMA)
Advanced wellnessalso —
What it isMethylmalonic acid is a metabolite that accumulates when B12 is functionally deficient inside cells, regardless of serum B12 levels.
DoesProvides the gold-standard functional marker of cellular B12 status.
GoodLow MMA confirms adequate cellular B12 even when serum B12 looks borderline.
BadElevated MMA reveals true cellular B12 deficiency, often missed by serum B12 alone, and predicts neuropathy and cognitive issues.
- Standard
- <0.4 µmol/L.
- Optimal
- 0.05–0.20 µmol/L (lower is good)
- Modifiers
- Rises in B12 deficiency, kidney disease.
How to optimize
- Lifestyle
- —
- Diet
- Animal foods for B12.
- Supplements
- Methylcobalamin (1000µg/day sublingual); higher doses or injections if persistent elevation.
- Peptides
- —
- Drugs
- Cyanocobalamin injections.
Reference ranges are general adult lab norms; optimal ranges are editorial picks from the longevity literature — not medical advice. Always interpret results with your physician.
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