Thiamine, or vitamin B1, is a water-soluble vitamin that is found naturally in certain foods, or in the form of supplements or even accepted industrially in foods. Thiamine plays an essential role in the growth and functioning of various cells.
Although the symptoms of thiamine deficiency were first recorded in ancient Chinese medicine texts, they were not linked to diet until the late 19th century. In 1884, a Japanese doctor found very high rates of illness and death among Japanese sailors who were on a rice-restricted diet for months at sea.
When given a more varied diet of whole grains, meats, beans and vegetables, disease and death rates virtually dropped. Around the same time, two Dutch scientists observed that chickens fed polished white rice developed leg paralysis, while chickens fed unpolished brown rice did not. Their observations led to the discovery of the presence of thiamine in the outer layers of rice that were removed during polishing.
What is the usual recommended amount?
RDI: The Recommended Dietary Allowance (RDA) for men aged 19 and over is 1.2 mg per day, and for women of the same age, 1.1 mg per day. While for women during pregnancy and lactation, the amount increases to 1.4 mg per day.
UL: The tolerable upper intake level (UL) is the maximum daily dose unlikely to cause adverse side effects in the general population. There is no AMT for thiamine due to the lack of reports showing negative effects of high thiamine intake.
Vitamin B1: A cell booster par excellence.
Due to its involvement in several basic cellular functions and the breakdown of nutrients into energy. A deficiency can lead to various brain and heart problems that require a constant supply of energy.
Food sources:
Thiamine is found naturally in meats, fish and whole grains. It is also added to breads, cereals and infant formula.
- Fortified breakfast cereals.
- Pig.
- Poisson.
- Beans, lentils.
- Green peas.
- Enriched cereals, breads, noodles, rice.
- Sun-flower seeds.
- Yogourt.
Signs of deficiency and toxicity.
Deficiency:
A thiamine deficiency is rare, as most people achieve RDAs through food. However, it can result from low intake of foods containing thiamine, decreased absorption in the gut, or increased loss in urine. As in the case of alcohol abuse or certain drugs such as diuretics.
A more severe thiamine deficiency can lead to beriberi, which causes muscle loss and decreased sensation in the hands and feet (peripheral neuropathy). As beriberi impairs reflexes and motor function, it can eventually lead to fatal fluid buildup in the heart and lower extremities.
Another consequence of severe thiamine deficiency often seen with alcohol abuse is Wernicke-Korsakoff syndrome. This neurodegenerative disease can lead to confusion, loss of muscle coordination and peripheral neuropathy. By the way, both types of deficiency are also seen in cases of gastrointestinal disorders. Such as celiac disease or bariatric surgery, or in people with HIV/AIDS. Treatment consists of high-dose supplements or intravenous injections, along with a balanced diet.
Symptoms appearing in case of mild to moderate deficiency:
- Weightloss
- Confusion, memory loss
- Muscular weakness
- Peripheral neuropathy
- Decreased immunity
Toxicity:
It is unlikely to reach a toxic level of thiamin from dietary sources alone. In the event of very high intakes, the body will absorb less of this nutrient and will eliminate any excess through the urine. There is no established level of toxicity for thiamine.
Did you know ?
Thiamine is destroyed by cooking at high temperatures or by long cooking times. It thus seeps into the water and will be lost in the cooking or soaking water which will be discarded. It can also be removed during food processing, as in the case of refined white bread and rice. This is why thiamin is fortified, or added, in many breads, cereals and grains that have undergone processing.