Vitamin B12 (Serum) Mass Concentration
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 or nerve damage."]
Key facts at a glance
- LOINC
- 55850-2
- Short code
- Vit B12 Ur-mCnc
- Synonyms
- Vit B12 Ur-mCnc
- 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 Is This Test Done?
Your doctor may order this test if you have symptoms like fatigue, weakness, numbness, or tingling in your hands and feet. It may also be used to check for vitamin B12 deficiency in people with conditions like pernicious anemia, celiac disease, or those who follow strict vegetarian or vegan diets. Sometimes, it’s part of a routine checkup for older adults, who are more prone to deficiencies.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. The process usually takes a few minutes. If you’re nervous, let your healthcare provider know—they can offer ways to make it more comfortable.
What the Results Mean
Low levels of vitamin B12 can indicate deficiency, which may require treatment like supplements or injections. High levels might suggest certain medical conditions or medications. Your doctor will discuss the results with you and explain what they mean for your health.
Common Reasons for Testing
This test is often done when symptoms like anemia, nerve problems, or unexplained fatigue appear. It may also be part of a broader evaluation for conditions like autoimmune diseases, malabsorption issues, or chronic illnesses.
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.
Vitamin B12 plays a critical role in preventing serious health problems, such as anemia, nerve damage, or cognitive decline. Deficiency can be hard to detect early because symptoms may develop slowly. Regular monitoring, especially in high-risk groups, helps catch issues before they worsen.
Short name
Vitamin B12 Level
Frequently asked questions
How long does it take to get the results of this test?
Can I eat or drink anything before this test?
What are the most common symptoms of vitamin B12 deficiency?
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