Vitamin B1 (thiamine) test
Quick answer: This blood test measures vitamin B1 (thiamine), which the body needs to turn food into energy and for nerve function. It is ordered when deficiency is suspected, such as with heavy alcohol use, severe vomiting, poor diet or after weight-loss surgery.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
How the test is done
- 1You are seated and your arm is cleaned
- 2Blood is drawn into a tube, often whole blood
- 3The sample is protected from light
- 4A plaster is applied
What your results can mean
Reading your report
Normal ranges differ between labs, so compare your result with the range printed on your report and discuss it with your doctor.
If the result is outside the usual range
A low level can be seen with heavy alcohol use, severe vomiting including in pregnancy, poor diet, weight-loss surgery or long-term diuretic use, and can affect nerves, heart and brain. High levels are rare and not usually a concern.
Who usually has this test
People with heavy alcohol use, severe or long vomiting, poor diet, after weight-loss surgery, or with unexplained nerve or heart symptoms.
Risks and aftercare
Mild soreness at the needle site may last a short while; if you are unwell, treatment is often started without waiting.
Names and options
Also called: thiamine level
Listed by the hospital as
- VITAMIN B1 (THIAMINE), BLOOD
Questions about this test
What is Wernicke's encephalopathy?
It is a serious brain condition caused by severe thiamine deficiency, often linked with heavy alcohol use or long vomiting. It can cause confusion, unsteadiness and eye movement problems and needs urgent treatment.
Can severe vomiting in pregnancy cause low thiamine?
Yes. Long-lasting severe vomiting in pregnancy, called hyperemesis gravidarum, can lower thiamine. Doctors often give thiamine to women with this condition.
Will treatment wait for the test result?
Often not. When deficiency is suspected and symptoms are serious, doctors usually give thiamine straight away because it is safe and delay can be harmful.
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Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
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This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.