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24-Hour Vitamin B1 (Thiamine) Intake Assessment

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

This test measures how much thiamine (vitamin B1) you consumed over the past 24 hours. It helps evaluate dietary intake and potential deficiencies.

Quick summary

["Understanding your vitamin B1 intake supports overall nutrition and nerve health."]

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

Key facts at a glance

LOINC
81927-6
Short code
Vit B1 intake 24h Est
Synonyms
Vit B1 intake 24h Est
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
20
Ref high
400
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
estimated
CPT
82670
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 Matters

Vitamin B1 is essential for energy metabolism, nerve function, and red blood cell production. A deficiency can lead to fatigue, nerve damage, or other health issues. This test helps ensure you’re meeting your daily needs.

How the Test Works

You’ll be asked to report your total thiamine intake from food and supplements over the past 24 hours. No blood or urine sample is drawn; this is a self-reported assessment.

What to Expect Before the Test

No special preparation is needed. Simply record your daily consumption of foods rich in thiamine (e.g., whole grains, pork, sunflower seeds) and any supplements containing vitamin B1.

Common Foods High in Vitamin B1

Thiamine is found in foods like fortified cereals, whole grains, pork, sunflower seeds, and nuts. If you’re unsure about your intake, check food labels or consult a dietitian.

Reference range

Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A

Specimen: serum

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.

◆Associated findings1

Short name

Vitamin B1 Intake (24h)

Frequently asked questions

This test is primarily used to assess dietary compliance, especially in patients with restrictive diets, eating disorders, or those at risk of thiamine deficiency (e.g., heavy alcohol use). It can help identify gaps in nutrition before symptoms develop.
This test does not measure blood levels of vitamin B1 but provides insight into whether your diet is sufficient. If your intake is low, your doctor may recommend dietary changes or supplements.
How long will it take to get results?
Results are typically available within a few days to a week, depending on your healthcare provider’s lab turnaround time.
Can I take this test at home?
No, this is a self-reported assessment completed during a medical visit or through a dietitian consultation. Your provider will guide you on how to document your intake accurately.
  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