The Methylmalonic Acid, GC/MS/MS, Urine (MMA) test contains 1 test with 2 biomarkers.
Description: Methylmalonic Acid Urine, also known as MMA, is a urine test used to detect Vitamin B12 deficiency early on before an individual becomes deficient or when there is a mild deficiency already present. MMA can also be used to diagnose methylmalonic acidemia in newborns.
Collection Method: Urine Collection
Specimen Type: Urine
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 Urine 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 CoA to succinyl CoA. They appear normal at birth, but as they consume protein, symptoms such excessive exhaustion, vomiting, dehydration, weak muscle tone, seizures, mental retardation, strokes, and severe metabolic acidosis emerge.
This test also checks creatinine urine levels.
Creatinine is a waste product created by muscles when a molecule called creatine is broken down. The kidneys eliminate creatinine from the body by filtering almost all of it from the blood and excreting it in the urine. The level of creatinine in the urine is measured in this test.
Creatine is a component of the energy-producing cycle that allows muscles to contract. The body produces both creatine and creatinine at a roughly steady rate. Because the kidneys filter almost all creatinine from the blood and excrete it in the urine, blood levels are usually an excellent predictor of how well the kidneys are operating. The amount produced is determined by the person's size and muscular mass. As a result, men's creatinine levels will be slightly higher than women's and children's.
Lab tests often ordered with a Methylmalonic Acid test:
- Vitamin B12
- Intrinsic Factor Antibody
- Complete Blood Count (CBC)
- Reticulocyte Count
- Parietal Cell Antibody
Conditions where a Methylmalonic Acid test is recommended:
- Vitamin B12 Deficiency
- Folate Deficiency
How does my healthcare 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.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.