Vitamin B12
Measures vitamin B12 levels.
About this test
Vitamin B12 testing helps investigate possible deficiency affecting blood cells or nerves.
Common reasons for testing
- Unexplained anemia, numbness, or other symptoms suggesting deficiency.
- Risk factors such as impaired absorption, certain medicines, or limited dietary B12.
These are examples of clinical uses. Your history and symptoms determine whether testing is appropriate.
What to expect
A small blood sample is taken from a vein in your arm. You may feel a brief pinch and have mild bruising. Tell the person collecting your sample if you have fainted with needles or take a blood thinner; keep pressure on the site afterward.
Appointment length
Your visit is expected to take about 15 minutes at our West Ashley location.
Categories
Preparation
- Tell the team about B12 pills or injections and when you last took them. Confirm any laboratory-specific fasting instructions.
- Bring a list of medicines and supplements, including biotin, vitamins, and hormones. Do not stop or change prescribed medicines unless your clinician tells you to.
Order requirement
No outside order needed
Understanding your results
- A borderline level may need methylmalonic acid or other follow-up testing.
- Recent supplements or injections can affect interpretation.
What happens next?
Review the report with your clinician alongside your symptoms, medical history, and earlier results. A value outside the reference range does not always mean disease, and a normal result does not explain every symptom. Confirm who will arrange any repeat or additional testing.
Sources & further reading
This patient summary draws on published clinical literature and professional guidance. Patient resources are identified separately below. Preparation also depends on your specific order and the collecting laboratory or imaging team.
- Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency
Frontiers in Molecular Biosciences, 2016
Content updated October 11, 2026. General education; individual advice comes from your care team.
Know the cost before your visit
Palmetto Preventive is a direct-pay service. You will see clear payment terms before your booking is finalized — no surprise lab bill.
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One transparent price for this test. Payment terms are presented before your booking is finalized.
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No surprise lab bill after your visit.
If testing is not approved, your payment is refunded in full.
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