Health Tests · Labcorp OnDemand
Vitamin B12 Test, $89
$89 · no doctor visit needed
- Order online, walk into 2,000+ locations — no appointment
- Physician order included — no doctor visit required
- Results in your portal in days
Same certified lab your doctor uses. HSA/FSA accepted.
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Order online for $89, walk into any of 2,000+ Labcorp locations — no doctor's visit needed. Measures vitamin B12 and folate in one blood draw, with results in a day — the pair worth testing together, because folate can mask a B12 problem.
The short version
$89, one walk-in visit, results in a day
The Vitamin B12 and Folate Test ($89) measures both vitamins in one blood draw — worth testing together because a folate supplement can correct the anemia of B12 deficiency while nerve damage quietly continues. Order online, walk in for the draw, results in a day. If your level comes back low, the next question is why — diet or absorption — and that is a clinician conversation.
Shopping links on this page go directly to Labcorp OnDemand. We don't earn a commission on orders.
Price
| Test | Price | |
|---|---|---|
| Vitamin B12 and Folate Test | $89 | Order now → |
Prices checked Nov 9, 2026. HSA/FSA eligible. Self-pay; insurance not billed.
What B12 and folate do — and why they are tested together
Vitamin B12 and folate (vitamin B9) work as a pair. B12 supports red blood cell formation, nerve function, cell metabolism, and DNA production; it comes almost entirely from animal foods, plus fortified foods and supplements. Folate helps the body make new red blood cells and DNA and is essential for fetal development; it comes from leafy greens, beans, seafood, and eggs. A deficiency in either can cause fatigue, weakness, and anemia — the symptoms overlap so closely that testing one without the other leaves the picture half-drawn.
Who is actually at risk of low B12
Labcorp lists the higher-risk groups as: adults 65 and older; people with autoimmune conditions such as atrophic gastritis and pernicious anemia; people with GI conditions such as celiac disease or Crohn’s disease; people who have had stomach or intestinal surgery; people following a strict vegetarian or vegan diet; people taking metformin for diabetes or antacids such as omeprazole, which can affect B12 absorption; and chronic alcohol users or people taking drugs such as phenytoin, methotrexate, or sulfa antibiotics, which can affect folate absorption. Pregnant and breastfeeding women have increased demand for folate. If none of these apply and you feel fine, a B12 test is a low-yield purchase — the test earns its keep when there is a reason to suspect deficiency.
Why folate can mask a B12 problem
This is the reason the combined test exists. High folate intake can correct the anemia caused by B12 deficiency — the blood counts look normal — while the nerve damage from untreated B12 deficiency continues unchecked. That is the classic trap: a folate supplement (or a folate-rich diet) hides the most visible sign of the deficiency that most needs catching. Testing B12 and folate together, and treating a low B12 even when the blood counts look fine, is how you avoid it. If you take a folic-acid supplement, tell your doctor — it changes how the numbers are read.
Early detection matters: left untreated, B12 deficiency can cause blood disorders and neurologic problems. Fatigue that does not resolve with sleep, numbness or tingling in hands and feet, balance problems, or a sore, smooth tongue deserve a clinician visit, not just a test order.
What the result can and cannot tell you
Serum B12 has a gray zone: a clearly low result points to deficiency, a clearly normal one is reassuring, and a borderline result (roughly 200–300 pg/mL on many labs’ ranges — read the range printed on your own report, because labs differ) needs context, usually a repeat draw or a follow-up marker such as methylmalonic acid or homocysteine, decided with your doctor. A normal B12 does not rule out functional deficiency, and a low B12 does not by itself say why — diet, absorption, or medication are different problems with different fixes. Supplements taken before the draw inflate the number, so note everything you take.
How walk-in B12 testing works
You order the test online, then visit a patient service center for a standard venous blood draw — no doctor’s order, no appointment, and no insurance needed. Results typically post to a secure portal 1 day after your sample arrives at the lab. HSA/FSA accepted. The one prep rule that matters: if you take a supplement containing biotin (vitamin B7, common in hair/skin/nail products), wait at least 72 hours from your last dose before the draw — biotin can interfere with the assay. No fasting is required for this test.
Common questions
Do I need to fast before a B12 test?
No. The prep note that matters is biotin: if you take a supplement containing biotin (vitamin B7, common in hair, skin, and nail products), wait at least 72 hours from your last dose before the blood draw, because biotin can interfere with the assay.
I take a B12 supplement — will it skew the result?
Yes. Recent B12 supplements raise serum B12, so the number reflects what you took as much as your stores. Tell your doctor what you take and when you last took it — do not stop a prescribed supplement just to test without asking first.
What is a normal B12 level?
Reference ranges vary by lab, but roughly 200–900 pg/mL is a common range, with 200–300 pg/mL often treated as borderline. Read the range printed on your own report — and treat a borderline result as a reason for follow-up (repeat draw, methylmalonic acid, or homocysteine), not a verdict.
Can a B12 test diagnose pernicious anemia?
No. The test shows a low B12 level; pernicious anemia — an autoimmune condition where the body cannot absorb B12 — needs further workup, such as intrinsic-factor antibody testing, with a clinician. The B12 result is the starting point, not the diagnosis.
How often should vegans test B12?
There is no fixed schedule. Because B12 comes almost entirely from animal foods, people on a strict plant-based diet rely on fortified foods or supplements, and many clinicians suggest checking levels periodically — annually is a common cadence. Ask your doctor what fits your diet and supplement routine.
Ready to order?
Get your B12 number this week
Order the Vitamin B12 and Folate Test for $89 and walk in this week — no doctor visit required.