Methylmalonic Acid Test-Why am I having this test?

The methylmalonic acid (MMA) test is done to measure the amount of MMA in your blood. You may have this test to check for:

• A lack (deficiency) of vitamin B12.
• A lack of nutrients in your diet (malnutrition).
• Disorders that affect how your body absorbs nutrients from food (malabsorption).

This test may also be done:

• If you had previous vitamin B12 tests and had unclear (ambiguous) results. This test can detect early and mild forms of vitamin B12 deficiency.
• As part of routine tests for newborns at the hospital (newborn metabolic screenings). This test checks for a disease in which the body is unable to process some proteins and fats (methylmalonic acidemia).

What is being tested?

MMA is a substance that combines with vitamin B12 in the body. When vitamin B12 decreases, MMA increases.

What kind of sample is taken?

A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.

How do I prepare for this test?

Do not drink alcohol starting at least 8 hours before your test, or as long as told by your health care provider.

How are the results reported?

Your results will be reported as a value that tells you how much MMA is in your blood. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges are:

• Newborn: 0.2–2 μmol/L.
• 4 days old: 0.24–0.39 μmol/L.
• 6 weeks to 6 months old: 0.36–1.51 μmol/L.
• 1–10 years old: 0.11–0.17 μmol/L.
• 11–15 years old: 0.13–0.22 μmol/L.
• 16–19 years old: 0.12–0.18 μmol/L.
• Adult: 0–0.4 μmol/L.

What do the results mean?

Results within the reference range are considered normal, meaning that you have normal levels of MMA in your blood.

Results that are higher than the reference range mean that you have too much MMA in your blood. This may result from:

• Vitamin B12 deficiency. This may be caused by conditions such as:
  • Pregnancy.
  • Liver disease.
  • A bone marrow disorder.
  • Thyroid disease.
• Kidney disease.
• Methylmalonic acidemia.

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

Ask your health care provider, or the department that is doing the test:

• When will my results be ready?
• How will I get my results?
• What are my treatment options?
• What other tests do I need?
• What are my next steps?

Summary

• Methylmalonic acid (MMA) testing is done to check the amount of MMA in your blood.
• MMA is a substance that combines with vitamin B12 in the body. As vitamin B12 decreases, MMA increases.
• Talk with your health care provider about what your results mean. This test can detect early and mild forms of vitamin B12 deficiency.