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Vitamin B12 (Serum) with Mass Concentration Measurement

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of vitamin B12, a vital nutrient essential for nerve function and red blood cell production, in your blood.

Quick summary

["Vitamin B12 helps prevent anemia and supports nerve health—low levels may signal deficiencies or underlying health concerns."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
18374-9
Short code
Vit B2 24h Ur-mCnc
Synonyms
Vit B2 24h Ur-mCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like fatigue, weakness, numbness, or tingling in your hands and feet. It can also be part of evaluations for pernicious anemia, digestive disorders, or other conditions affecting nutrient absorption.

What Does the Test Involve?

You’ll have a small needle inserted into your arm to draw blood. The sample is then sent to a lab for analysis to determine your vitamin B12 concentration.

What to Expect Before the Test

No special preparation is needed, but inform your provider about any medications you’re taking, especially those that may affect blood clotting or vitamin levels.

What Are Common Results?

Results are typically reported as a mass concentration value (e.g., picograms per milliliter). While reference ranges vary by lab, low levels may indicate deficiency, while high levels could signal other conditions like kidney disease or certain cancers.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Vitamin B12 Level

Frequently asked questions

What Might Low or High Results Mean?
Low vitamin B12 levels can cause anemia, nerve damage, or cognitive issues. High levels may require further investigation, as they can sometimes be linked to conditions like kidney disease or certain cancers.
How Often Should I Get This Test?
Your provider will determine frequency based on your health status, symptoms, and medical history. Regular monitoring may be recommended if you have conditions like pernicious anemia or malabsorption disorders.
Can I Eat or Drink Before the Test?
You can eat and drink normally before the test unless instructed otherwise by your provider. Avoiding certain foods or supplements (like vitamin B12 supplements) may be advised if your test is part of a specific evaluation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy