Lab marker · High

High Methylmalonic acid (MMA): what it means

A Methylmalonic acid (MMA) result above the normal range is considered high. Here is what a raised Methylmalonic acid (MMA) can point to, and when it is worth discussing with a doctor.

Reference range: ~70–270 nmol/L; a raised MMA confirms true tissue-level B12 deficiency, useful when a borderline B12 is ambiguous

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What a high Methylmalonic acid (MMA) can mean

  • True vitamin B12 deficiency — the main reason; confirms a tissue-level deficiency when the serum B12 is borderline.
  • Kidney impairment — reduces MMA clearance and can raise it independently of B12.
  • Rare inherited metabolic disorders (methylmalonic acidaemia) — very high levels, usually diagnosed in childhood.

When to discuss with a doctor

MMA is a second-line, confirmatory test rather than a routine one. It earns its place when a serum B12 sits in the borderline zone and the clinical question — is this person truly B12 deficient? — needs settling, especially with suggestive symptoms (fatigue, tingling, a macrocytic anaemia) or in vegans, older adults and those with absorption problems. A raised MMA (with a normal kidney function) supports genuine deficiency and treatment, while a normal MMA is reassuring. Mediora.AI shows MMA alongside B12, folate and the red-cell size so the deficiency question is read together; the treatment decision belongs with your doctor.

Conditions this can relate to

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Mediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.