Methylmalonic Acid Urine Test, GC/MS/MS

What is the purpose of this test?

The Methylmalonic Acid (MMA) Urine Test, GC/MS/MS, is a specialized diagnostic tool used to evaluate your body'svitamin B12 status. Methylmalonic acid builds up in the body when there isn’t enough vitamin B12, which is essential for nerve health, red blood cell production, and DNA synthesis. This test measures the level of MMA in your urine using gas chromatography/tandem mass spectrometry (GC/MS/MS), a highly sensitive method that ensures precise detection. Because MMA levels increase early in vitamin B12 deficiency, it serves as a reliable early marker—sometimes even before symptoms appear or before serum B12 levels drop significantly.

By identifying elevated MMA levels, the test can help doctors diagnose functional vitamin B12 deficiency, even when other B12 test results seem normal.This is especially important for individuals with unexplained fatigue, memory issues, or tingling sensations, which could be early signs of neurological damage due to low B12. It is also used to monitor treatment effectiveness in patients already receiving B12 supplementation. Regular testing may help prevent long-term complications by allowing for early intervention and personalized nutritional or medical support.

Who should get this test?

The Methylmalonic Acid Urine Test, GC/MS/MS, may be recommended for individuals who:

• Show symptoms of vitamin B12 deficiency, such as fatigue, tingling, or memory issues.
• Have low or borderline levels of vitamin B12 on a standard blood test.
• Follow a vegan or vegetarian diet, which may lack sufficient B12.
• Have gastrointestinal disorders (like Crohn’s disease or celiac disease) that affect nutrient absorption.
• Are older adults at higher risk for B12 deficiency due to decreased stomach acid production.
• Are being treated with B12 and need to monitor their response.
• Have a history of gastric bypass surgery or other procedures affecting B12 absorption.
• Are infants or children suspected of having inherited metabolic disorders involving methylmalonic acid.

When should I order the Methylmalonic Acid Urine Test, GC/MS/MS?

Individuals may consider ordering this test if they have symptoms or exposure concerns related to vitamin B12 deficiency.

Symptoms to consider:

• Numbness or tingling in the hands and feet.
• Unexplained tiredness or low energy.
• Mood changes, depression, or memory problems.
• Pale skin or shortness of breath.
• Trouble with balance or walking.
• Digestive issues like poor appetite or weight loss.
• A strict plant-based diet with little or no animal products.

If you experience these symptoms or suspect you may have low vitamin B12 levels, the Methylmalonic Acid Urine Test, GC/MS/MS, can provide helpful information for you and your doctor to create a plan for treatment and long-term health.