Methylmalonic Acid (MMA)

The Methylmalonic Acid (MMA) test contains 1 test with 1 biomarker.

Brief Description: The Methylmalonic Acid (MMA) test is a medical laboratory analysis that measures the level of methylmalonic acid in the blood or urine. Methylmalonic acid is a substance produced in small amounts during the metabolism of certain amino acids and fats. Elevated levels of MMA may indicate an underlying metabolic disorder.

Also Known As: MMA Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Methylmalonic Acid test ordered?

When a vitamin B12 test result comes back low, an MMA test may be performed, sometimes coupled with a homocysteine test.

Asymptomatic persons with a higher risk of vitamin B12 insufficiency, such as the elderly, or those using certain medicines for a long period, such as Metformin, are also given MMA. If the two tests are not scheduled together, an MMA test may be ordered as a follow-up to an increased homocysteine level.

When a doctor fears that an acutely unwell child has inherited methylmalonic acidemia, MMA testing may be recommended.

What does a Methylmalonic Acid blood test check for?

Methylmalonic acid is a naturally occurring chemical that is required for human metabolism and energy generation. Vitamin B12 aids in the conversion of methylmalonyl CoA to succinyl Coenzyme A in one step of metabolism. If there isn't enough B12, the MMA concentration rises, resulting in an increase in MMA levels in the blood and urine. Methylmalonic acid levels that are high in the blood or urine are a sensitive and early sign of vitamin B12 insufficiency.

Anemia and the formation of big red blood cells can occur as a result of vitamin B12 deficiency over time. It can also induce neuropathy symptoms including numbness and tingling in the hands and feet, as well as mental or behavioral problems like cognitive impairment, disorientation, irritability, and depression in severe cases. Though some patients may have some degree of neuropathy, an increased concentration of MMA may frequently be detected before blood cell alterations and full-blown symptoms appear.

Although the link between MMA and B12 has been recognized for over 40 years, MMA testing is not widely used, and there is no consensus on its clinical relevance. Some doctors believe that MMA is a better indicator of bioavailable B12 than the standard vitamin B12 test since a considerable portion of B12 detected in the blood is bound to proteins and is not biologically active. Others feel that measuring MMA and homocysteine can help detect early and mild B12 insufficiency. Others believe that many moderate deficits diagnosed do not evolve to more serious deficiencies and so do not require identification or treatment.

Methylmalonic acidemia is a rare metabolic condition that affects roughly 1 in 25,000 to 100,000 people. Testing babies for high levels of MMA could help doctors diagnose it. Screening for this disease is required in all 50 states in the United States. This condition prevents babies from converting methylmalonyl Coenzyme A to succinyl Coenzyme A.

Lab tests often ordered with a Methylmalonic Acid test:

When an MMA test is ordered, it's often part of a broader evaluation of potential Vitamin B12 deficiency and related health issues. Here are some tests commonly ordered alongside it:

1. Vitamin B12 (Cobalamin) Level:

   • Purpose: To measure the level of Vitamin B12 in the blood.
   • Why Is It Ordered: To directly assess Vitamin B12 levels, as deficiency is a common cause of elevated MMA. This test helps confirm the diagnosis.

2. Complete Blood Count (CBC) with Differential:

   • Purpose: To evaluate overall blood health, including red and white blood cells, and platelets.
   • Why Is It Ordered: Vitamin B12 deficiency can lead to megaloblastic anemia, characterized by large, immature red blood cells.

3. Homocysteine:

   • Purpose: To measure the level of homocysteine in the blood.
   • Why Is It Ordered: Elevated homocysteine levels can also be a consequence of Vitamin B12 deficiency and are associated with cardiovascular risk.

4. Folate (Folic Acid) Level:

   • Purpose: To measure the level of folate in the blood.
   • Why Is It Ordered: Folate deficiency can cause similar hematological abnormalities as Vitamin B12 deficiency, and both need to be assessed to ensure proper diagnosis and treatment.

5. Intrinsic Factor Antibody and Parietal Cell Antibody Tests:

   • Purpose: To test for antibodies that may indicate pernicious anemia, an autoimmune cause of Vitamin B12 deficiency.
   • Why Is It Ordered: To identify the underlying cause of Vitamin B12 deficiency, especially if pernicious anemia is suspected.

6. Reticulocyte Count:

   • Purpose: To measure the number of young red blood cells in the blood.
   • Why Is It Ordered: To assess bone marrow function and the body’s response to anemia treatment.

7. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: Liver disease can affect the storage and metabolism of Vitamin B12.

8. Kidney Function Test:

   • Purpose: To evaluate kidney function.
   • Why Is It Ordered: Kidney dysfunction can affect MMA levels, and renal impairment needs to be considered when interpreting MMA results.

These tests, when ordered alongside a Methylmalonic Acid test, provide a comprehensive view of the potential causes and effects of Vitamin B12 deficiency. They are crucial for diagnosing the deficiency, determining its severity, identifying the underlying cause, and monitoring the effectiveness of treatment. The specific combination of tests will depend on the individual’s symptoms, medical history, and initial test results.

Conditions where a Methylmalonic Acid test is recommended:

A Methylmalonic Acid test is often ordered in the following conditions or diseases:

1. Vitamin B12 Deficiency: To diagnose and monitor vitamin B12 deficiency, which can lead to anemia, neurological symptoms, and other health issues.

2. Metabolic Disorders: To diagnose certain inherited metabolic disorders, such as methylmalonic acidemia or other conditions that affect the body's ability to metabolize methylmalonic acid.

How does my health care provider use a Methylmalonic Acid test?

The methylmalonic acid test can be used to determine a vitamin B12 deficiency that is mild or early. It can be ordered alone or in conjunction with a homocysteine test as a follow-up to a vitamin B12 test result that falls below the normal range.

MMA is a chemical produced in the body in extremely minute amounts. It is required for metabolism and the creation of energy. Vitamin B12 aids in the conversion of methylmalonyl CoA to succinyl Coenzyme A in one step of metabolism. If there isn't enough B12, the MMA level rises, resulting in an increase in MMA levels in the blood and urine. Methylmalonic acid levels in the blood or urine can be used to detect vitamin B12 insufficiency early.

There are currently no standards for screening asymptomatic adults for vitamin B12 deficiency, however those at high risk without symptoms, such as the elderly or those taking particular drugs for a long time, may require confirmation with MMA and/or homocysteine.

The MMA test is quite sensitive in detecting a B12 deficiency. It is the preferred confirmatory test for a B12 deficiency because it is more specific than homocysteine.

MMA testing may be conducted in some cases to assist detect methylmalonic acidemia, a rare inherited metabolic condition. In all 50 states in the United States, newborn screening programs currently require testing for this disease.

What do my Methylmalonic Acid test results mean?

Early stages of B12 deficiency may be evident if MMA and homocysteine levels are elevated while vitamin B12 levels are mildly diminished. This could indicate a decrease in B12 availability in the tissues.

If only the homocysteine level is high but not the MMA, the person may be deficient in folate. This distinction is critical because treating anemia with folate treats the anemia but not the brain damage, which may be irreparable.

If both MMA and homocysteine levels are within normal limits, a B12 shortage is unlikely.

Infants with the rare hereditary illness methylmalonic acidemia may have moderately to severely high levels of MMA.

Reduced MMA levels are uncommon and are not considered clinically significant.

Most Common Questions About the Methylmalonic Acid test:

Understanding the Methylmalonic Acid Test

What is the Methylmalonic Acid (MMA) test?

The Methylmalonic Acid test is a laboratory test used to measure the amount of methylmalonic acid in the blood or urine. Elevated levels of methylmalonic acid can indicate a deficiency of Vitamin B12, as this vitamin is necessary for the breakdown of methylmalonic acid in the body.

Why is the Methylmalonic Acid test important?

The Methylmalonic Acid test is important because it can help diagnose Vitamin B12 deficiency, which can lead to conditions such as pernicious anemia, nerve damage, and cognitive difficulties.

What do the results of the Methylmalonic Acid test mean?

Normal levels of methylmalonic acid vary depending on the lab and the method used for testing. Generally, higher than normal levels of methylmalonic acid can indicate a Vitamin B12 deficiency.

Interpreting Methylmalonic Acid Test Results

What does a high result in the Methylmalonic Acid test mean?

A high result in the Methylmalonic Acid test can indicate a Vitamin B12 deficiency. It may also indicate a condition called methylmalonic acidemia, a rare genetic disorder.

Can a person have a normal result in the Methylmalonic Acid test and still have a Vitamin B12 deficiency?

It's unlikely, but possible. The Methylmalonic Acid test is very sensitive to Vitamin B12 deficiency. However, the test may miss some cases, especially if the deficiency is mild or just beginning.

How are the results of the Methylmalonic Acid test used in the treatment of Vitamin B12 deficiency?

The results can guide the treatment plan. For instance, if the test shows elevated methylmalonic acid levels, Vitamin B12 supplementation may be recommended.

Methylmalonic Acid Test and Specific Populations

How is the Methylmalonic Acid test used in the elderly?

In the elderly, the Methylmalonic Acid test can help diagnose Vitamin B12 deficiency, which is common in this age group and can lead to conditions like anemia and dementia.

Can the Methylmalonic Acid test be used in people with pernicious anemia?

Yes, people with pernicious anemia often have a Vitamin B12 deficiency, and this test can help diagnose it.

Can the Methylmalonic Acid test be used in people with suspected nerve damage due to Vitamin B12 deficiency?

Yes, if nerve damage is suspected due to Vitamin B12 deficiency, this test can help confirm the deficiency.

General Questions about the Methylmalonic Acid Test

Can the Methylmalonic Acid test monitor the effectiveness of treatment for Vitamin B12 deficiency?

Yes, decreasing levels of methylmalonic acid can indicate that Vitamin B12 supplementation is effective.

Can certain medications affect the results of the Methylmalonic Acid test?

Yes, certain medications such as antibiotics, oral contraceptives, and metformin may affect the results of this test.

Can the Methylmalonic Acid test be used in people with digestive disorders?

Yes, digestive disorders like Crohn's disease and celiac disease can cause malabsorption of Vitamin B12, leading to a deficiency. This test can help diagnose the deficiency.

Can the Methylmalonic Acid test be used in people with autoimmune disorders?

Yes, autoimmune disorders like pernicious anemia can affect the body's ability to absorb Vitamin B12, and this test can help diagnose a resulting deficiency.

How does the Methylmalonic Acid test assist in diagnosing methylmalonic acidemia?

Methylmalonic acidemia is a rare genetic disorder characterized by the inability to break down methylmalonic acid, leading to its buildup. This test can help diagnose this condition.

Can the Methylmalonic Acid test be used in people with renal disease?

Yes, but with caution. Renal disease can also lead to elevated methylmalonic acid levels, which may not necessarily indicate a Vitamin B12 deficiency.

Can the Methylmalonic Acid test assist in diagnosing malnutrition?

Yes, malnutrition can lead to Vitamin B12 deficiency, which can be identified using this test.

How does the Methylmalonic Acid test assist in diagnosing conditions resulting from alcoholism?

Alcoholism can lead to nutritional deficiencies, including Vitamin B12 deficiency. This test can help identify such deficiencies.

Can the Methylmalonic Acid test be used to assess overall nutritional status?

Yes, as part of a broader assessment, this test can provide information about a person's nutritional status, particularly regarding Vitamin B12 levels.

How does the Methylmalonic Acid test aid in diagnosing conditions related to poor dietary habits?

Poor dietary habits can lead to Vitamin B12 deficiency, especially in people who don't consume animal products, as Vitamin B12 is mostly found in animal-based foods. This test can help diagnose such a deficiency.

Can the Methylmalonic Acid test be used to assess the nutritional status of vegetarians and vegans?

Yes, because Vitamin B12 is mostly found in animal-based foods, vegetarians, and especially vegans, may be at risk of Vitamin B12 deficiency. This test can help diagnose such a deficiency.

How does the Methylmalonic Acid test aid in diagnosing conditions related to poor absorption of nutrients?

Conditions that impair nutrient absorption, like celiac disease or Crohn's disease, can lead to Vitamin B12 deficiency. This test can help diagnose the deficiency.

How does the Methylmalonic Acid test assist in diagnosing conditions in people with obesity?

While obesity doesn't directly cause Vitamin B12 deficiency, people with obesity may have poor dietary habits that can lead to such a deficiency. This test can help diagnose it.

Can the Methylmalonic Acid test assist in diagnosing conditions in people with autoimmune disorders?

Yes, autoimmune conditions like pernicious anemia can lead to Vitamin B12 deficiency. This test can help diagnose this deficiency.

Can the Methylmalonic Acid test help in diagnosing conditions related to certain medications?

Yes, certain medications can affect the body's ability to absorb Vitamin B12. This test can help diagnose any resulting deficiencies.

How does the Methylmalonic Acid test aid in diagnosing conditions in newborns?

Newborns can inherit methylmalonic acidemia, a rare genetic disorder that causes a buildup of methylmalonic acid. This test can help diagnose this condition.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.