Focus on one of the most important soldiers for our health.

Thiamine, or vitamin B1, is a water-soluble vitamin that is found naturally in certain foods, in supplement form, or even industrially introduced into foods. Thiamine plays an essential role in the growth and functioning of various cells.

Although symptoms of thiamine deficiency were first recorded in ancient Chinese medical texts, they were not linked to nutrition until the late 19th century. in 1884 a Japanese doctor found that among Japanese sailors who were on a diet of rice for months at sea, there was a great deal of sickness and death.

A more varied diet of whole grains, meats, beans and vegetables has substantially reduced the number of illnesses and deaths. Around the same time, two Dutch researchers noticed that chickens fed polished white rice developed leg paralysis, while chickens fed unpolished brown rice did not. Their observations made it possible to determine the presence of thiamine in the outer layers of rice, which were removed during polishing.

What is the usual recommended amount?

RDI: The Recommended Daily Allowance (RDI) is 1.2 mg per day for men 19 years of age and older, and 1.1 mg per day for women of the same age. For women during pregnancy and breastfeeding, the amount increases to 1.4 mg per day.

UL: The Tolerable Upper Intake Level (UL) is the highest daily dose that is unlikely to cause adverse side effects in the general population. There is no thiamine AMT because there are no reports of adverse effects of high thiamine intake.

Vitamin B1: A great cell booster.

Because of its involvement in several key cellular functions and the breakdown of nutrients into energy. A deficiency can lead to a variety of brain and heart problems that require a constant supply of energy.

Food sources:

Thiamine is found naturally in meat, fish and whole grains. It is also added to bread, cereal and baby formula.

  • Fortified breakfast cereal.
  • Pork.
  • Fish.
  • Beans, lentils.
  • Green peas.
  • Enriched cereals, bread, pasta, rice.
  • Sunflower seeds.
  • Yogurt.

Signs of deficiency and toxicity.


Thiamine deficiency is rare because most people meet the RDA through food. However, this may be due to low thiamine-rich food intake, reduced intestinal absorption, or increased urine loss. As in the case of alcohol abuse or certain drugs such as diuretics.

More severe thiamine deficiency can lead to avitaminosis, which causes muscle wasting and loss of sensation in the arms and legs (peripheral neuropathy). Because vitamin deficiency impairs reflexes and motor function, it can eventually lead to fatal fluid accumulation in the heart and lower extremities.

Another consequence of severe thiamine deficiency, often seen in alcohol abuse, is Wernicke-Korsakoff syndrome. This neurodegenerative disease can cause confusion, loss of muscle coordination, and peripheral neuropathy. By the way, the lack of both types is also observed in gastrointestinal disorders. Such as people with celiac disease or bariatric surgery or HIV/AIDS. Treatment consists of high-dose supplements or intravenous injections along with a balanced diet.

Symptoms that occur with mild to moderate deficiency:

  • Weight loss
  • Confusion, memory loss
  • Muscle weakness
  • Peripheral neuropathy
  • Decreased immunity


Toxic levels of thiamine are unlikely to occur from dietary sources alone. Consuming too much will cause the body to absorb less of this nutrient and eliminate the excess in the urine. The level of toxicity of thiamine has not been determined.

Do you know ?

Thiamine is destroyed by high temperature cooking or prolonged cooking. So it seeps into the water and will be lost in the cooking or soaking water, which will be thrown away. It can also be removed by food processing, as in refined white bread and rice. This is why thiamin is fortified or added to many processed breads, cereals and grains.

* Presse Santé aims to communicate health information in a language accessible to all. IN NO EVENT SHOULD THE INFORMATION PROVIDED BE A SUBSTITUTE FOR THE ADVICE OF A HEALTH CARE PROFESSIONAL.

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