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Thiamine (Vitamin B1) Serum Concentration

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

This test measures the amount of thiamine (vitamin B1) in your blood. Thiamine is essential for proper nerve function, energy metabolism, and brain health.

Quick summary

["Thiamine levels help assess risk for deficiency, especially in chronic alcohol use or malabsorption disorders."]

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

Key facts at a glance

LOINC
2998-3
Short code
Vit B1 Bld-mCnc
Synonyms
Vit B1 Bld-mCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like muscle weakness, nerve pain, confusion, or heart issues that could be linked to low thiamine levels. It’s also used in monitoring patients with conditions like alcoholism, kidney disease, or poor nutrition.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your lab uses a fasting protocol. Bring any medications you’re currently taking to your appointment.

How the Test Works

A blood sample is taken from a vein in your arm. The sample is sent to a lab where thiamine levels are measured using a specialized immunoassay or enzymatic method to detect its presence.

What the Results Mean

Results are compared to reference ranges for healthy adults, but exact values can vary by lab. Low levels may indicate deficiency, while high levels could suggest recent thiamine intake or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low thiamine levels can lead to neurological issues (e.g., neuropathy, memory problems), cardiovascular complications, or metabolic disturbances. High levels are less commonly clinically significant unless tied to medication use or lab error.

Short name

Vitamin B1 Blood Level

Frequently asked questions

Could I get this test at home?
No, this test requires a blood draw from a healthcare provider. Some at-home vitamin tests exist but are not standardized for thiamine measurement.
What causes thiamine deficiency?
Chronic alcohol use, poor diet (low in whole grains, meat, or fortified foods), malabsorption disorders (e.g., celiac disease), or certain medications (e.g., diuretics) can lower thiamine levels.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Follow-up with your doctor if you have questions about your results.
  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