Methylmalonate Test

Methylmalonate is an organic acid that accumulates when vitamin B12 is insufficient at the cellular level. Vitamin B12 is required for mitochondrial energy production, red blood cell formation, and nervous system maintenance. Because blood B12 levels can appear normal despite functional deficiency, methylmalonate provides a more sensitive indicator of intracellular B12 status. Elevated levels are associated with fatigue, neuropathy, cognitive changes, and impaired metabolic efficiency.