Not just your B12 level — whether your cells can use it
The short answer
Comprehensive B12 Deficiency Panel bundles 3 tests — Vitamin B12, Methylmalonic Acid (MMA) and Homocysteine — for $79.99 all-in (about $26.66 per test). Fast 8–12 hours before the draw; results post in 5–12 business days. Physician-authorized with no doctor's visit or insurance needed; one draw at Quest or Labcorp.
Other Labs
Starting at $193
+ lab fees
TestWell
$79.99
A serum B12 test alone misses early and borderline deficiency — levels can look 'normal' while your cells are already running short. This panel adds the two functional markers clinicians use to settle the question: methylmalonic acid (MMA), which accumulates early and specifically when usable B12 is low, and homocysteine, which rises with both B12 and folate deficiency. Read together, the pattern is diagnostic: elevated MMA with elevated homocysteine points to true B12 deficiency, while elevated homocysteine with normal MMA points to folate instead. It's the right panel when B12 came back borderline, when deficiency symptoms (fatigue, numbness and tingling, brain fog, memory changes) persist despite a normal B12, or when you're verifying that supplementation is actually working. Note: MMA is a specialty assay, so results take longer than routine bloodwork.
Vitamin and nutrient testing identifies deficiencies that can drive fatigue, immune dysfunction, neurological symptoms, and long-term disease risk — and confirms that supplementation is working.
Anyone with restrictive diets (vegan, low-fat, low-carb), malabsorption conditions, fatigue, hair loss, mood changes, or currently supplementing and wanting to verify dosing.
Sample Type
Blood draw
Fasting
Required
Results In
5–12 business days
Biomarkers
3 across 3 tests
3 individual tests · 3 biomarkers measured — each test linked so you can learn more.
Fasting for 8–12 hours recommended (homocysteine reads most accurately fasted). Water is okay. MMA is a specialty send-out assay — allow extra time for results.
A Comprehensive B12 Deficiency Panel costs $79.99 at TestWell — $85.99 all-in when ordered alone, because the $6 lab processing fee is charged once per order, with no draw fee or physician fee added. With insurance, what you pay depends on your deductible and your plan's negotiated rate; TestWell's price is fixed before the draw and is HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest or Labcorp) | $79.99 | $85.99 | Includes the one $6 lab processing fee, charged once per order |
Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Starting at $193 at other labs
TestWell Price
$79.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Individual tests that complement this panel
Comprehensive B12 Deficiency Panel
$79.99