Vitamin B12 (Serum Concentration) – Confirmatory Test
This test measures the amount of vitamin B12 (also called cobalamin) in your blood to check if your body has enough of this essential nutrient.
["Vitamin B12 helps keep your nerves and blood cells healthy and is crucial for energy and brain function."]
Key facts at a glance
- LOINC
- 55884-1
- Short code
- Vit B12b Ur-sCnc
- Synonyms
- Vit B12b Ur-sCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 200
- Ref high
- 900
- 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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like fatigue, numbness, tingling in the hands or feet, dizziness, or memory problems. It could also be done if you have conditions like pernicious anemia, certain dietary restrictions (e.g., veganism), or if prior tests suggested low vitamin B12 levels.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm, and a few drops of blood will be collected into a tube. The process usually takes a few minutes and is generally painless.
What the Results Mean
Results are compared to a reference range for healthy adults. Low levels may indicate vitamin B12 deficiency, which can be caused by poor diet, absorption issues, or certain medical conditions. High levels may require further investigation to rule out other factors.
Common Causes of Low Vitamin B12 Levels
Deficiency can result from dietary lack (e.g., not eating enough meat, fish, or dairy), conditions that interfere with absorption (like atrophic gastritis or pernicious anemia), or medications that reduce vitamin B12 absorption.
Reference range
NCBI: Vitamin B12 200-900 pg/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Vitamin B12 (Confirm)
Frequently asked questions
What causes vitamin B12 deficiency?
How long does it take to get results from this test?
Can I take vitamin B12 supplements before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy