Methylmalonic Acid (Urine)
The Urine Methylmalonic Acid test measures MMA excretion to assess functional vitamin B12 status. It helps identify B12 deficiency at a cellular level.
Turnaround time
8 days
Biomarkers count
1
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Details about Methylmalonic Acid (Urine)
What is the Methylmalonic Acid (Urine) test?
The Methylmalonic Acid (MMA) urine test measures the amount of MMA excreted in urine. MMA accumulates when vitamin B12 is insufficient for normal metabolic processes, making it a sensitive marker of functional B12 deficiency.
Urine MMA testing reflects metabolic imbalance over time and may be used when blood testing is not available or as part of broader metabolic assessment. Results are often adjusted for creatinine to improve accuracy.
This test complements serum MMA and vitamin B12 testing.
Why do I need a Methylmalonic Acid (Urine) test?
Vitamin B12 deficiency can affect the nervous system, blood formation, and energy metabolism and may be missed by serum B12 testing alone.
You may benefit from this test if you:
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Have symptoms suggestive of B12 deficiency
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Have borderline or normal B12 levels with symptoms
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Have digestive conditions affecting absorption
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Follow a vegetarian or vegan diet
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Require non-blood-based testing
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Are monitoring response to B12 supplementation
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Have unexplained fatigue or neurological symptoms
The test helps confirm whether symptoms are related to impaired B12 metabolism.
Benefits of the test
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Sensitive marker of functional B12 deficiency
Detects cellular-level deficiency. -
Non-invasive testing option
Requires only a urine sample. -
Complements blood B12 and MMA testing
Adds metabolic insight. -
Useful when blood sampling is difficult
Suitable for selected patients. -
Reflects metabolic status over time
Less affected by short-term fluctuations. -
Supports neurological symptom investigation
Helps explain nerve-related symptoms. -
Widely used in metabolic assessment
Accepted marker of B12 deficiency. -
Useful for treatment monitoring
Tracks response to supplementation.
Step-by-step: How we offer testing
Clinic-based testing (UK-wide)
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Choose your nearest UK clinic
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Receive urine collection instructions
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Provide a urine sample
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Sample sent to the laboratory
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Results are issued once analysis is complete
Home or hotel collection (+£60, UK-wide)
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Urine collection kit provided
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Sample collected at home or hotel
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Sample returned for laboratory analysis
Your results explained
Low / normal MMA
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MMA within reference range
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UK standard (typical): <3.6 mmol/mol creatinine
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Suggests adequate vitamin B12 status
Mildly elevated MMA
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Slight increase above reference range
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UK standard (typical): 3.6–5.0 mmol/mol creatinine
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May indicate early or mild B12 deficiency
High MMA
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Markedly elevated MMA
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UK standard: >5.0 mmol/mol creatinine
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Strongly suggests functional vitamin B12 deficiency
Creatinine adjustment and kidney function should be considered during interpretation.
How It Works
Simple steps to get your results
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Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
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WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.