Methylmalonic Acid (MMA)
A more sensitive marker of B12 deficiency that often rises before serum B12 falls.
Consider this test if:
- Numbness, tingling, balance issues, brain fog, or low mood that may point to B12 deficiency
- Borderline or low-normal serum B12 that needs a clearer answer
- Macrocytic anemia, pernicious anemia, gastrectomy, or malabsorption raising B12 deficiency risk
- A long-term vegan or vegetarian diet, or age over 60
- Checking whether B12 injections or supplements are correcting a known deficiency
- HSA/FSA eligible
- Typical results in 3-6 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No strict fasting is required. If you take B12 supplements or receive injections, note the dose and timing, since active repletion lowers MMA and is exactly what a follow-up test is checking. For a clean baseline assessment of deficiency, discuss with your clinician whether to test before starting or restarting B12.
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What this test is for
Methylmalonic acid (MMA) is a small molecule produced when the body breaks down certain amino acids and fats. Vitamin B12 is the cofactor that converts MMA into succinate, so when B12 is in short supply, MMA accumulates in the blood, often in the early stages while serum B12 still reads normal or low-normal. That early rise makes MMA the test of choice to confirm B12 deficiency when symptoms point that way: fatigue, numbness or tingling, balance problems, memory trouble, low mood, or unexplained macrocytic anemia, especially in older adults who can have neurological signs without anemia.
This is the serum MMA test, the standard way to confirm functional B12 status and to track whether B12 supplementation is working. A urine MMA (creatinine-ratio) version exists for the same metabolic question, and the combined MMA and homocysteine panel adds homocysteine to widen the workup. If you supplement B12, MMA also tells you whether the dose is actually correcting the deficiency.
- Specimen
- Serum or plasma
- Measures
- Substance concentration
What you'll learn
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Insights that connect the dots. A clinician reads your whole picture, not one result in isolation, connecting family history, past results, and lifestyle into clear next steps.
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Your personalized action plan. Nutrition, supplements, and training in one clinician-reviewed protocol, updated as your results change.
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Track your trends. Upload results from any lab and see each biomarker trend over time, so you know what is working.
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Never miss a recheck. Mito tells you what is worth retesting and when, then reminds you so nothing slips.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in 3-6 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost, covering the lab and what it takes to run the service. It is never a profit on the test itself. Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9 per month, and any applicable lab order or draw fee is itemized before you pay.
Where do I get tested?
Choose an available partner lab at checkout. If your cart contains multiple blood tests, Mito helps consolidate the eligible tests at one lab when possible. At-home kits and scans follow the collection or appointment process shown on their product page.
Is this eligible for HSA/FSA?
Yes. Eligible tests can be paid for with an HSA or FSA card at checkout.
When will I get my results?
Your results appear in your Mito dashboard after the laboratory completes processing. A clinician then reviews them before your analysis and personalized action plan are finalized. Timing varies by test, and specialty assays and at-home kits may take longer.
Do I need a doctor's order?
No. Mito provides the laboratory order when one is required, so you do not need to arrange a separate doctor visit before purchasing.
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