B-12 ANEMIA

Methylmalonic acid

Methylmalonic acid is another important component in diagnosing vitamin B12 deficiency anemia.   Just because you have a blood test where your vitamin B12 levels are low, doesn’t necessarily mean that you have B12 anemia.  Your doctor will determine the amount of methylmalonic acid in your blood by ordering (yet another – get used to it) a blood test.  This blood test will help determine whether or not a vitamin B12 deficiency exists.

According to wikipedia.com, the definition of methylmalonic acid is a dicarboxylic acid that is a C-methylated derivative of malonate.  In easier terms, the methylmalonic acid in your body is a substance that is produced when the amino acids in your body break down.

The methylmalonic acid test is primarily ordered by doctors for help with diagnosing B12 deficiency.  It may also be ordered to check for certain genetic disorders such as methylmalonic acidemia.  Testing for methylmalonic acidemia is usually done as part of the many blood tests performed on newborns.

While range values can differ depending on the laboratory that performs the test, normal methylmalonic acid levels are usually considered to be from 0.08 to 0.56 micromoles per liter.  If your values are greater then what the normal range indicates it might be due to vitamin B12 deficiency.  It can also indicate a genetic disease (methylmalonic acidemia).

Once you have been found to have low levels of vitamin B12, the methylmalonic acid test will be ordered along with the test for homocysteine levels.  It has been suggested that using the methylmalonic acid test as a screening tool to discover B12 deficiency would be beneficial, especially with the elderly.  However this is very controversial and only a handful of doctors use the methylmalonic acid test for this purpose.  If your methylmalonic acid and homocysteine levels are normal it is unlikely that a B12 deficiency exists.  Even if vitamin B12 levels appeared low in previous tests.

Methylmalonic acid levels may also be increased with kidney disease.  The methylmalonic acid accumulates in the blood and is not excreted in the urine.  While an elevated methylmalonic acid test may indicate a B12 deficiency, the levels of methylmalonic acid does not mean anything specific when it comes to the B12 deficiency.  The symptoms you feel, the severity of your deficiency or the likely hood of any progression are not based on the number that results from your test.  It has been found that there is a high variation rate in methylmalonic acid tests when they are continually measured over time.