The methylmalonic acid blood test measures the amount of methylmalonic acid in the blood.
How the Test is Performed
How to Prepare for the Test
No special preparation is necessary.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterwards there may be some throbbing or slight bruising. This soon goes away.
Why the Test is Performed
Methylmalonic acid is a substance produced when proteins, called amino acids, in the body break down.
The health care provider 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.
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.
What Abnormal Results Mean
A higher than normal value may be due to vitamin B12 deficiency or methylmalonic acidemia.
Veins and arteries vary in size from one person 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, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 164.
Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar SU, eds. Avery's Diseases of the Newborn. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 22.
Update Date 11/1/2015
Updated by: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.