What is Vitamin B1

Anyone that takes multivitamins will be aware of the distinctive smell some of them have. This smell is usually due to thiamine, which like many sulfur-containing compounds is slightly malodorous. The primary dietary sources are pork, beef, liver, unrefined grain products, yeast products and nuts.

Thiamine is converted into pyrophosphate, which acts as a coenzyme in some vital carbohydrate metabolic process. The metabolism of alcohol depends on thiamine pyrophosphate. As a triphosphate, it is needed in normal nerve conduction.

An interesting bit of information about thiamine is that when taken in moderate doses of 100mg three-time a day, it produces a substance in sweat that insects do not like. Although debatable thiamine may be an effective insect repellant. Thiamine is excreted in the urine as pyrimidine when the tissue is saturated.

Deficiency in B1 makes it so that not enough ATP is generated to help the cells maintain cellular and biological function. Secondly, there is an accumulation of keto acids and lactic acid within the cells.  The other set of reaction that depends on the availability of B1 is the pentose phosphate pathway. The pentose phosphate pathway is important because it helps protect the cell from the stressors that happen during metabolism and other cellular activities. Failure of the pentose pathway can lead to damage in several intracellular structures.

Deficiency in thiamine leads to a condition called beriberi, another word for weakness. This disease is mainly found in countries where rice is the main staple food. When the natural rice grains are refined, the thiamine containing part of the of the rice is removed as well, hence the deficiency. Beriberi is less common today in western countries because foods are fortified with vitamins.

Beriberi is categorized into two groups depending on whether the condition is chronic or acute. In chronic, the main important feature is polyneuropathy of the peripheral nerves which results in a loss in motor control. In acute deficiency states or wet beriberi, B1 deficiency leads to an enlargement of the heart and eventually cardiac failure.

In Westernised society beriberi like symptoms are often seen in individuals who drink a lot of alcohol and have a poor diet. Because they are also lacking in various vitamins, in this case, other symptoms are present as well as those of dry and wet beriberi. The most disturbing is the Wernicke – Korsakoffe Syndrome. This syndrome results in poor memory, apathy, and eye disturbances. There have been suggestions in Australia that the vitamin should be added to beer to help prevent the condition (Molnar, Donadelli, & Aldrich, 2017)

Thiamine is used to treat people who have heart disease, metabolic disorders, ageing, canker sores, cataracts, glaucoma and motion sickness. The most interesting part about B1 is perhaps the interaction between deficiency in B1 and dementia. There is a great deal of literature in the last century that shows that thiamine deficiency is associated with neurological problems. This includes cognitive deficits and encephalopathy.

Research also reviews many similarities between classical deficiency in thiamine and Alzheimer’s disease. This is because both are associated with cognitive deficits and reduction in brain glucose metabolism. Thiamine-dependent enzymes are essential components of glucose metabolism that are reduced in the brain of AD patients. Thiamine decline and a reduction in their levels could be the reason for the decrease in glucose metabolism.
Some preclinical trials have reviewed that reduced thiamine can drive AD like abnormalities, which includes memory deficits, neuritic plaques, and hyperphosphorylation of tau. Tau is a group of proteins that stabilize microtubules, they are found mainly in the neurons of the central nervous system. Pathologies and dementias of the nervous system such as Alzheimer’s diseases and Parkinson are associated with Tau that has become defective.

Studies now indicate that brains of people who suffer from the AD are functionally deficient in thiamine, hence determining how thiamine is restored in the brain may provide vital information in the treatment of people with Alzheimer’s Disease (Gibson et al., 2016).

Foods high in B1

  • Lean pork chops
  • Brown rice
  • Salmon
  • Green peas
  • Navy beans
  • Firm Tofu
  • Asparagus
  • Navy Beans
  • Cabbage


In western countries, thiamine deficiency is fairly uncommon however here are some risk factors that may contribute to B1 deficiency.

  • Alcohol dependence
  • Old age
  • Diabetes
  • Bariatric surgery
  • Dialysis
  • High-dose diuretic use

Symptoms include 

  • Loss of Appetite
  • Fatigue
  • Irritability
  • Reduced reflexes
  • Tingling sensation in the arms and legs
  • Muscle weakness
  • Delirium and short of breath

Clinical Consideration 

Thiamine malabsorption often happens in people with alcohol problems, cirrhosis of the liver or GI diseases. The first few doses of thiamine must be given parenterally to ensure maximum absorption and good clinical response. People who consume more than 60g of alcohol per day should be considered at risk of developing thiamine deficiency.



Molnar, L., Donadelli, R., & Aldrich, C. (2017). 226 Retention of thiamine and other water soluble vitamins in a wet pet food application. Journal of Animal Science, 95(supplement4), 111-112.

Gibson, G. E., Hirsch, J. A., Fonzetti, P., Jordan, B. D., Cirio, R. T., & Elder, J. (2016). Vitamin B1 (thiamine) and dementia. Annals of the New York Academy of Sciences, 1367(1), 21-30.

Ridley, N. J., Draper, B., & Withall, A. (2013). Alcohol-related dementia: an update of the evidence. Alzheimer’s research & therapy5(1), 3.



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