10.32 Thiamin Deficiency & Toxicity

Thiamin deficiency is rare in developed countries, but still occurs in poorer countries where white (aka polished) rice is a staple food. During the polishing process, thiamin, and many other nutrients, are removed. Some people also have a mutation in THTR1 that causes them to become thiamin deficient1. Thiamin deficiency is known as beriberi, which, when translated, means “I can’t, I can’t.” The symptoms of beriberi are illustrated in the link below.

Web Link


There are two major forms of beriberi: dry and wet. Dry beriberi affects the nervous system, with symptoms such as loss of muscle function, numbness, and/or tingling. Wet beriberi affects the cardiovascular system resulting in pitting edema, along with enlargement of the heart1. A picture of a person with beriberi is shown below.

Figure 10.321 A person suffering from beriberi2

Another group that is at risk for thiamin deficiency is alcoholics. There are three reasons why alcoholics are prone to becoming deficient3:

1. Alcohol displaces foods that are better sources of thiamin

2. Liver damage decreases TPP formation

3. Increased thiamin excretion

The thiamin deficiency found in alcoholics is known as Wernicke-Korsakoff Syndrome. Symptoms of this condition include paralysis or involuntary eye movement, impaired muscle coordination, memory loss and confusion3. The following video shows some of the symptoms of this condition.

Web Link

Video: Wernicke-Korsakoff Syndrome (First 1:50)

Thiamin toxicity has never been reported as a result of oral intake. Thus, there is little worry about thiamin toxicity4.

References & Links

1. http://www.nlm.nih.gov/medlineplus/ency/article/000339.htm

2. http://en.wikipedia.org/wiki/File:Beriberi_USNLM.jpg

3. Gropper SS, Smith JL, Groff JL. (2008) Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Publishing.

4. Stipanuk MH. (2006) Biochemical, physiological, & molecular aspects of human nutrition. St. Louis, MO: Saunders Elsevier.


Beriberi – http://www.moondragon.org/health/graphics/beriberi1.jpg

Wernicke-Korsakoff Syndrome – http://www.youtube.com/watch?v=wDcyBXJAZNM