Also known as: B12 Test, Cobalamin
The short answer
Essential for nerve function, energy production, and red blood cell formation, measured from a standard blood draw. At TestWell it costs $25.99 plus a $6 lab fee, needs no fasting, and results post in 2–4 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest or Labcorp.
Hospital Lab
$100
cash pay
Other Labs
$49
+ lab fees
TestWell
$25.99
+ $6 lab fee
Vitamin B12 is crucial for nerve function, DNA synthesis, red blood cell production, and brain health. Deficiency can cause fatigue, weakness, numbness and tingling, memory problems, and anemia. It's especially common in vegans/vegetarians, older adults, and those taking certain medications like metformin or proton pump inhibitors.
Essential for nerve function and red blood cell production. Deficiency causes fatigue, neuropathy, megaloblastic anemia, and (if prolonged) irreversible neurologic damage.
Vegans/vegetarians, anyone over 50, people on metformin or PPIs (both deplete B12), patients with unexplained fatigue, brain fog, tingling/numbness, or balance issues.
Sample Type
Blood draw
Fasting
Not required
Results In
2–4 business days
Performed At
Quest or Labcorp
Your Vitamin B12 results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 2–4 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you.
No fasting required. Biotin supplements may interfere — stop 72 hours before.
The short answer
Worth it if you have fatigue, nerve symptoms, or a reason to be low - and genuinely valuable for vegans, older adults, and anyone on metformin or long-term acid reducers. At $25.99 it is a cheap, high-yield test; a B12 deficiency is very treatable once you know it is there.
We would rather you order the right test than the most expensive one.
Vitamin B12 is a simple venous draw at Quest or Labcorp, or an at-home mobile draw where available - no fasting required. One prep note that trips people up: high-dose biotin supplements can interfere with the assay, so stop biotin for 72 hours before your draw. If B12 is borderline, pairing it with methylmalonic acid (MMA) or [folate](/tests/folate) confirms a true tissue deficiency.
The markers that matter most and what an out-of-range value can mean. Reference ranges vary by lab, age and sex.
| Marker | Typical range | What it means |
|---|---|---|
| Vitamin B12 (serum) | ~200-900 pg/mL | Under ~200 pg/mL indicates deficiency; 200-300 is borderline and often confirmed with an MMA test; high levels are usually just supplementation and rarely a concern on their own. |
This section medically reviewed by Youmna DiStefano, MD — updated July 2026. General health information, not medical advice; interpret results with a qualified clinician.
A Vitamin B12 test costs $25.99 at TestWell — $31.99 all-in when ordered alone, because the $6 lab processing fee is charged once per order, with no draw fee or physician fee added. Ordered directly from the labs' own consumer sites, the same test lists at $49.00 at Quest Health and $49.00 at Labcorp OnDemand (list prices checked Sep 12, 2026). Hospital outpatient labs typically bill around $100.00 self-pay for the same test, and often more. 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. Full cost breakdown →
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest or Labcorp) | $25.99 | $31.99 | Includes the one $6 lab processing fee, charged once per order |
| Quest Health (Quest Diagnostics' own site) | $49.00 | $49.00 | list price checked Sep 12, 2026 |
| Labcorp OnDemand (Labcorp's own site) | $49.00 | $49.00 | list price checked Sep 12, 2026 |
| Hospital outpatient lab, self-pay (typical) | $100.00 | $100.00 | Reference figure; hospital charges vary widely by facility and are often higher |
35% less than the lower lab-direct list price, for the same draw at the same lab. Lab test codes: Quest test code 927 · Labcorp test no. 001503 · BioReference code 0160-2. Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
TestWell Price
$25.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Better value: the Comprehensive B12 Deficiency Panel
Save $23.98This test is part of the Comprehensive B12 Deficiency Panel — 3 tests · 3 biomarkers for $79.99, $23.98 less than à la carte.
$79.99$103.97
3 tests · 3 biomarkers
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$25.99