Individual test · Labcorp 706961

Methylmalonic Acid, Serum or Plasma

This test measures the amount of methylmalonic acid (MMA) in your blood, a substance that builds up if your body lacks Vitamin B12. It helps show whether you have a Vitamin B12 deficiency, which can cause fatigue or nerve problems, even if other vitamin tests appear normal. This measurement helps rule out other causes of these symptoms by confirming if the body is truly struggling to use B12. However, it cannot identify the specific reason for low vitamin levels or diagnose kidney disease, which can also cause high MMA levels.