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Vitamins & Nutrients

Vitamin B12 Test

A vitamin essential for nerve function and red blood cell formation. Found in animal foods.

Physician reviewed
Results in 1–3 days
4,000+ lab locations

What is Vitamin B12?

A vitamin essential for nerve function and red blood cell formation. Found in animal foods.

Vitamin B12 Reference Range

These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.

PopulationRange
age 18+200 – 1100 pg/mL

Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.

What your Vitamin B12 result may mean

Lower than range

Common in vegetarians/vegans, older adults, and people on metformin or acid-suppressing medications. Can cause anemia and neurological symptoms.

Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.

Related Vitamins & Nutrients biomarkers

Markers commonly tested alongside Vitamin B12.

Frequently asked

No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.

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