Vitamin B12 (Cobalamin) 24-Hour Urinary Excretion Rate
This test measures how much vitamin B12 your body excretes in urine over a 24-hour period. It helps assess how well your kidneys are processing and removing vitamin B12 from your system.
["This test can help diagnose kidney-related vitamin B12 issues or rule out malabsorption problems."]
Key facts at a glance
- LOINC
- 14947-6
- Short code
- VMA 24h Ur-sRate
- Synonyms
- VMA 24h Ur-sRate
- 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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like fatigue, numbness, or tingling in your hands and feet, or if you’ve been diagnosed with kidney disease. It may also be used to evaluate vitamin B12 levels in patients with unexplained anemia or other neurological concerns.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to collect your urine over a full 24-hour period, starting and ending at the same time each day. Some labs may provide instructions on how to properly store the urine samples.
What the Test Involves
After collecting your urine samples, they are sent to a lab where they are analyzed to measure the amount of vitamin B12 excreted. The test does not require drawing blood.
Possible Results and Interpretation
Results are compared to a reference range that varies by lab. Low levels may suggest kidney dysfunction or impaired vitamin B12 processing, while normal levels help confirm healthy excretion.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal results can indicate conditions like vitamin B12 deficiency (even if blood levels appear normal), kidney disease, or certain metabolic disorders. High excretion rates might be less common but could signal unusual metabolic processing. Always discuss results with your healthcare provider for personalized interpretation.
Short name
Vitamin B12 Urine Rate
Frequently asked questions
What causes vitamin B12 excretion to be tested?
How is this test different from a standard vitamin B12 blood test?
Can diet affect this 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 16, 2026. · Read our editorial policy