Insufficiency of vitamin B1 (thiamine). Hypovitaminosis and avitaminosis B, (beriberi, alimentary polyneuritis) occur with a lack of food in this vitamin (preferential feeding polished rice in East and South-East Asia), a violation of its absorption in the intestines and digestion (with severe intestinal lesions occurring with A violation of absorption, persistent vomiting, prolonged diarrhea, etc.). Predispose to the development of the disease pregnancy and lactation, heavy physical labor, febrile illness, thyrotoxicosis, diabetes mellitus. The daily requirement of an adult in vitamin B- is about 2 mg. Vitamin B., is part of a number of enzymes involved in carbohydrate metabolism; In the body turns into cocarboxylase, which is a prosthetic group of enzymes involved in carbohydrate metabolism. In the development of a complete clinical picture of vitamin B deficiency, the concomitant deficiency of other B vitamins is also important.

Clinical picture. The disease is characterized by a common defeat of peripheral nerves (polyneuritis), cardiovascular system and edema. The first complaints are general weakness, fatigue, headache, dyspnoea and palpitations during exercise. Then the polyneurite phenomena join:
Paresthesia and lowering the skin sensitivity of the lower extremities, and later other parts of the body, a feeling of heaviness and weakness in the legs, rapid fatigue when walking, lameness. Calf muscles become hard, painful on palpation. The walk of the sick beriberi is characteristic: they attack the heel and then the outer edge of the foot, sparing fingers. Further, tendon reflexes are extinguished, muscular atrophies occur. Violation of the cardiovascular system is manifested by tachycardia, dystrophic changes in the heart muscle with circulatory failure, lowering of blood pressure, mainly diastolic. There are also symptoms of dystrophic lesions and disorders of the functions of the digestive system, vision disorders, mental disorders. In accordance with the prevailing symptoms, the edematous form (with more severe cardiovascular system and edema) and dry (with the predominant lesion of the nervous system), as well as the acute, malignant "fulminant" form, often ending with death, are prominent. It is difficult to recognize beriberi in children of early childhood.

The diagnosis is established based on the history (the nature of nutrition, the presence of diseases that promote the manifestation of thiamine deficiency), the characteristic changes in the cardiovascular and nervous systems; The diagnosis is confirmed by biochemical studies: it is evident that the reduction of thiamine in the daily urine is below 100 μg, in the hour (on an empty stomach) - below 10 μg, the content of cocarboxylase in erythrocytes is below 20-40 μg / l. Characteristic increase in the content of pyruvic acid in the plasma (above 0.01 g / l) and increased its excretion in the urine (more than 25 mg / day). Recently, a number of more sophisticated modern methods have also been used for this purpose.

Differential diagnosis with infectious (with poliomyelitis, diphtheria, etc.) and toxic polyneuritis (poisoning with mercury, methyl alcohol, phosphorus, etc.) is based on taking into account the epidemic situation, the history of the disease, as well as the results of biochemical studies of thiamine metabolism. Differential diagnosis of edematic beriberi with myocarditis, myocardial dystrophy is facilitated by the presence of polyneuritis symptoms.

Treatment in severe and moderate cases is stationary. The regime is bedding. Assign vitamin B, 30-50 mg / m or p / c with a subsequent transition to oral administration; Simultaneously prescribe nicotinic acid (25 i; v}, riboflavin (10-20 mg), vitamin B6. Symptomatic therapy: cardiovascular drugs, diuretics, to increase the tone of the nervous system-strychnine injection (1: 1000 to 1-1.5 Mg) .In endogenous insufficiency of vitamin B, caused by chronic diseases of the intestine - their treatment.

Prevention. High-grade, rich in vitamin B, nutrition, timely diagnosis and treatment of diseases in which the absorption of vitamin B1 is impaired.