Vitamins
Vitamin B1 (Thiamine)
Also known as: B1, Thiamin
CONVERT & COMPARE
nmol/L
=
3.32
µg/dL
=
3.32
mcg/dL
=
3.32
ug/dL
Reference ranges by source
Published adult intervals: 3, from 3 named sources, shown in nmol/L.
About Vitamin B1 (Thiamine)
B vitamins are nutrients that your body needs to work well and stay healthy. There are eight different types. A vitamin B test checks the level of one or more B vitamins in a sample of your blood or urine (pee).
Vitamin B1 (thiamine) helps your body break down and use carbohydrates and certain amino acids for energy. Not getting enough thiamine is most often linked to heavy alcohol use or chronic illness. Early signs of low thiamine can include poor appetite, irritability, low mood, and feeling weak. Long-term thiamine deficiency can cause a serious condition called beriberi.
You get B vitamins from many foods, including leafy green vegetables, meats and fish, eggs, whole grains, milk, and other dairy products. A lack of vitamin B is rare in the United States, because many foods have added B vitamins. These foods include cereals, breads, and pasta.
Main source: MedlinePlus ↗
Useful for
Checking for thiamine (vitamin B1) deficiency in people with symptoms such as poor appetite, weakness, irritability, or changes in mood
Evaluating people at higher risk of vitamin B1 deficiency, such as those with heavy alcohol use or chronic illness
Helping diagnose beriberi, a serious condition caused by long-term thiamine deficiency
Investigating symptoms that suggest you may not be getting enough of one or more B vitamins
Main source: MedlinePlus ↗
Interpretation
Your results will show the amount of vitamin B1 (thiamine) that was tested. If your levels are normal but you still have symptoms, you may need other tests to find the cause.
If your thiamine level is low, your provider will look for the reason. Common causes include heavy alcohol use, malnutrition, or another long-term illness. You may need other tests to confirm the diagnosis.
Treatment usually involves taking thiamine supplements. In more serious cases, vitamins may be given by intravenous (IV) treatment.
If you have questions about your results, talk with your provider.
For general wellness information only. Talk to a clinician about your specific results.
Main source: MedlinePlus ↗
Track your vitamin b1 (thiamine) in MyBloodTest
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Related biomarkers
More tests in the vitamins category.
Sources
Last updated 2026-05-02
This page presents source-specific reference data and sourced explanations. For general wellness information only. This is not medical advice. For diagnosis or treatment of any condition, talk to a qualified clinician.