Vitamin B12 (Cobalamin) Level
This test measures the amount of vitamin B12 (also called cobalamin) in your blood. Vitamin B12 is essential for nerve function, red blood cell production, and DNA synthesis.
["Vitamin B12 helps prevent serious health issues like anemia and nerve damage."]
Key facts at a glance
- LOINC
- 96809-9
- Short code
- Cyanocobalamin IgE Qn
- Synonyms
- Cyanocobalamin IgE Qn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- 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, weakness, numbness, tingling in the hands or feet, or trouble with balance and coordination. It may also be ordered if you have conditions like pernicious anemia, gastric bypass surgery, or certain dietary restrictions (e.g., veganism). Additionally, it could be part of routine screening for people with chronic illnesses or those taking certain medications that interfere with B12 absorption.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a fasting blood draw, but this is not always required. Bring any medications or supplements you’re taking, as they could affect results.
A blood sample is drawn from a vein in your arm using a needle. The blood is then sent to a lab for analysis using an immunoassay method to detect vitamin B12 levels.
The test involves drawing blood from your arm, which may cause a slight sting or discomfort. The process usually takes a few minutes. You may feel lightheaded or dizzy afterward, especially if you haven’t eaten recently.
What the Results Mean
Results are reported as a numeric value representing the concentration of vitamin B12 in the blood. Low levels may indicate vitamin B12 deficiency, which can cause health problems if untreated. High levels may suggest other conditions or medications affecting absorption.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low vitamin B12 levels can lead to anemia (reduced red blood cells), nerve damage, cognitive issues, or weakness. Deficiency is often linked to poor diet, malabsorption, or conditions affecting the stomach or intestines. High levels may require further investigation to rule out conditions like liver disease or certain medications.
Short name
Vitamin B12
Frequently asked questions
What causes vitamin B12 deficiency?
How long does it take to get results?
Can I take supplements to raise my vitamin B12 levels?
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 16, 2026. · Read our editorial policy