Methylmalonic acid is a substance produced when proteins (called amino acids) in the body break down.

A test can be done to measure the amount of methylmalonic acid in your blood.

A blood sample is needed. For information on how this is done, see: Venipuncture

No special preparation is necessary.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Your doctor may order this test if there are signs of certain genetic disorders, such as methylmalonic acidemia. Testing for this disorder is often done as part of a newborn screening exam.

This test may also be done with other tests to check for a vitamin B12 deficiency.

Normal values are 0.08 to 0.56 micromoles per liter.

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

Greater than normal values may be due to vitamin B12 deficiency or methylmalonic acidemia.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Antony AC. Megaloblastic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 167.