Biochemistry

CHAPTER 12. VITAMINS 12.1 GENERAL CONCEPT OF VITAMINS AND THEIR CLASSIFICATION The discovery of vitamins is closely related to the study of the role of individual nutrients in providing nutritious food. Back in the middle of the 19th century, it was believed that for normal functioning of the body, it is sufficient to have protein, fats, carbohydrates, mineral salts and water in food. However, experience has shown that this is not so. In 1880, on the basis of experiments on animals, the Russian biochemist and doctor N.I.Lunin found that in food products along with well-known nutrients there are vital chemical compounds. Further N.I.Lunin conclusions were confirmed and developed by other scientists, in particular I.O.Sosnin (1891), F. Hopkins (1906-1912), K.Funk(1912). The Polish biochemist K. Funk identified the active principle in rice bran and discovered the presence of amino groups in them, then suggested to call all substances of this kind vitamins (from Latin vita - life), i.e. amines of life. However, it turned out that not all substances of this class contain an amino group. Nevertheless, the term "vitamin" has been widely used for all mandatory additional nutritional factors. Diseases of humans and animals associated with the lack of vitamins in food, K.Funk called "vitamin deficiency". In addition to beriberi, he also classified scurvy, pellagra, rickets, and some other diseases as vitamin deficiencies. After the work of K.Funk, the science of vitamins - vitaminology was further developed, and significant progress was made in this area over the next decades. In the USSR., among the studies devoted to this problem are works of N.V.Bukina, A.V.Palladin, L.A.Cherkess, M.N.Shatemikova, M.I.Smimova. Currently, more than 30 vitamins are known, their chemical structure has been decrypted, which made it possible to synthesize most of them. Vitamins are a group of low molecular weight organic substances of various chemical natures, with a variety of physiological properties and necessary for the body in minimal quantities. They perform catalytic and regulatory functions. Vitamins are characterized by a number of features. 1. Vitamins are not a plastic material or an energy source unlike other essential substances (amino acids, polyunsaturated fatty acids, etc.). 2. Vitamins are active in minimal amounts. The daily need for them is calculated in thousandths and even millionths of a gram. 241