Thiamine participates in metabolic processes of carbohydrates, proteins and fats, as well as in synthesis of enzymes and nervous system regulation.
The daily requirement of this vitamin for adults depends on age and physical activity and can vary from 1 to 2.5 mg, while for children it is normally from 0.5 to 2 mg.
When a person consumes less than 0.4 mg of thiamine per day for a long time, in a couple of months he can start suffering from vitamin B1 avitaminosis – specifically, the beriberi disease. Beriberi is mostly common in Asian countries where polished white rice forms a major part of the diet. Indeed, as you can see in table 17, 100 grams of brown rice contains 0.52 mg of thiamine, while 100 grams of polished rice contains just 0.08 grams!
Avitaminosis can also occur as a result of eating white bread made of refined flower, pasta, various cakes and pastry, as well as canned meat and fish for a long time. These products contain little thiamine and its consumption increases when there is an excess of carbohydrates and proteins.
Among first signs of avitaminosis are headache, weakness in the legs, bad sleep, irritability. What happens next is loss of appetite and weight, tachycardia and shortness of breath. In acute cases there is a burning pain in different body parts and limbs can lose sensation.
Fortunately, beriberi is very rare in our region and if you eat more or less diverse food, you will not run out of thiamine (except cases when absorption and digestion of thiamine is disturbed).
Thiamine is widely used for treating many diseases. For example, it is used to improve heart functioning, strengthen heart medicines effect and increase urinary flow.
This vitamin is also often prescribed in the last one and a half months of pregnancy (up to 20 mg per day) for preventing postpartum bleeding. It is also used to cure rheumatism, various infections and also during surgeries etc.
It is important to know that thiamine in pills causes allergic reactions in around 2% of cases. Therefore, the best way of receiving it, as well as all the other vitamins, is through having a complex diet.
Now let’s talk about “inevitable” losses. Like ascorbic acid, thiamine is destroyed when heated in alkaline medium. As always, the losses are proportional to the complexity and duration of cooking. For example, when you boil grains and vegetables, up to 15% of the vitamin is lost. When you fry vegetables for an hour, up to 30% is destroyed. Cooking meat for an hour destroys 23% of thiamine and for two hours up to 44%. When you fry meat, the content of thiamine is reduced by nearly 40% and when you stew it, the level of thiamine can be reduced by 56%.Text: from the book A.Eddar "Treatise of nutrition". Interpreter: Liza Dukhova