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Vitamin B12 (Serum) Titration (Quantitative Measurement)

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

This test measures the amount of vitamin B12 in your blood to check if your body has enough of this essential nutrient.

Quick summary

["Vitamin B12 helps prevent nerve damage and supports red blood cell production."]

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

Key facts at a glance

LOINC
104440-3
Short code
PV3 Ab sp2 Titr Ser IA
Synonyms
PV3 Ab sp2 Titr Ser IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 numbness, weakness, fatigue, or trouble with balance and coordination. It could also be done if you have conditions like pernicious anemia, stomach surgery, or certain dietary restrictions that might affect vitamin B12 levels.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the blood draw if your test involves a specific timing (e.g., 24-hour collection). Bring any medications you’re taking to your appointment.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm using a small needle. The blood will be sent to a lab for analysis using a sensitive immunoassay method to detect vitamin B12 levels.

What the Results Mean

Low levels may indicate vitamin B12 deficiency, which can cause health problems over time. High levels might suggest certain medical conditions or exposure to substances that interfere with testing. Your provider will discuss results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Vitamin B12 Level (Serum)

Frequently asked questions

What causes low vitamin B12 levels?
Low vitamin B12 levels can result from poor diet (e.g., vegan/vegetarian diets without fortified foods), conditions affecting absorption (like pernicious anemia or stomach surgery), or certain medications. Symptoms may include fatigue, tingling, or memory issues.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your provider will contact you once they’re ready to review them with you.
Can I eat or drink before this test?
Most vitamin B12 tests don’t require fasting, but if your provider specifies a 24-hour urine collection or other timing, follow their instructions carefully. Avoid caffeine or alcohol before blood draws if recommended.
  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