Thiamin: Water-Soluble Vitamin Deficiency & Toxicity Symptoms

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Riboflavin: Water-Soluble Vitamin Deficiency & Toxicity Symptoms

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 Thiamin
  • 0:48 Beriberi
  • 1:58 Wernicke-Korsakoff Syndrome
  • 3:35 Toxicity
  • 4:02 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

Thiamin (B1) is a water-soluble vitamin that is easily flushed out of the body. If the level of thiamin in the body is too low, it will result in a deficiency disease, such as beriberi or Wernicke-Korsakoff syndrome. There's no toxic level of thiamin.


When rice is picked from the field, it has a brown appearance. This is because the rice kernel is naturally covered by a bran layer. This brown rice can be eaten as is, or the rice kernels can be sent to the mill where the bran layer is removed, turning the brown rice into white rice. This processing helps prevent spoilage and makes the rice a bit easier to chew, but it also strips the rice of important vitamins and nutrients.

One of the vitamins that gets stripped away is thiamin, also known as B1, which is a B-complex vitamin needed for proper nerve function and glucose metabolism. In this lesson, we will learn more about thiamin and what happens to your body if you get too little or too much of this important vitamin.


Thiamin (B1) deficiency is when you get too little B1. This can result in a disorder called beriberi, which is a condition characterized by weakness and neurological symptoms. Heart changes may also be seen depending on the type of beriberi present. Beriberi means 'I cannot,' which refers to the extreme weakness that comes with this condition. To help you recall this term you might want to think of beriberi as the disorder that makes you so weak you can 'barely, barely' walk.

This weakness comes about because a thiamin (B1) deficiency makes it hard to break down glucose for energy. Since glucose is the primary energy source for your nerve cells and your brain, you end up feeling worn out, both physically and mentally. Additional neurological symptoms, ranging from tingling sensations in the hands and feet to paralysis, may be due to the fact that thiamin is needed to make neurotransmitters, which are chemical substances that relay a message from a nerve cell to another cell. In beriberi, the lack of thiamin means the message does not go through.

Wernicke-Korsakoff Syndrome

People living in the United States do not typically suffer from beriberi, even if they consume a lot of refined grains. This is because grains eaten in developed countries like the U.S. tend to be enriched, which means vitamins, such as thiamin, are added back after the grain is processed. Food sources for thiamin, in addition to enriched grains, include pork, seeds and legumes, which are things like beans, lentils and peas.

Yet, thiamin deficiency is still seen in populations of the world that consume processed grains that are not enriched and where other thiamin-rich foods are unavailable. We also want to remember that thiamin, like other B-complex vitamins, is a water-soluble vitamin, which means that it dissolves in the watery environment of the body and is easily flushed out of the body. Because of this, thiamin needs to be replenished regularly for good health.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account