Vitamins are a large group of complex organic compounds of a variety of chemical nature. Vitamins in small amounts are extremely necessary for the metabolism of each organism. In other words, they provide the very existence of the organism, it is not without reason that they were called vitamins - from the Latin word "vita" - "life". Vitamins are usually called the letters of the Latin alphabet. With a lack of vitamins (beriberi) in humans and animals, a number of serious diseases develop which can lead to death. The importance of certain types of food to prevent certain diseases was known in ancient times. So, the ancient Egyptians knew that the liver helps from night blindness. It is now known that night blindness can be caused by a lack of vitamin A. A disadvantage, for example vitamin D at an early age, causes rickets in humans and animals, and a lack of vitamin C contributes to scurvy. The founder of the doctrine of vitamins was the Russian scientist N.I. Lunin, who discovered their role in 1880.

Vitamins are a large group of complex organic compounds of a variety of chemical nature

In the human body and animals, vitamins come with food or are administered as medicinal preparations: vitamins A, a group of vitamins B, C, D, E, and others. The main source of vitamins are plants. There are plants that are so rich in vitamins that they are called "vitamin-bearing plants".

Vitamins are easily destroyed by boiling and storing, so it is better to use plants in raw form. Very rich in vitamin C - rose hips, lemon, black currant berries. Sources of vitamin A - carrots, tomatoes. Breeders produced varieties roses, whose fruits contain a record number of vitamin C.

The concentration of vitamins in tissues and the daily requirement for them is small, but with insufficient intake of vitamins, the body experiences characteristic and dangerous pathological changes. Most vitamins are not synthesized in the human body, so they must regularly and in sufficient amounts enter the body with food or in the form of vitamin-mineral complexes and food additives. Exceptions are vitamin D, which is formed in the skin of a person under the influence of ultraviolet light; vitamin A, which can be synthesized from precursors entering the body with food; and niacin, the precursor of which is the amino acid tryptophan.

Until now, the classification of vitamins was based on their solubility in water or fats. Therefore, the first group consisted of water-soluble vitamins (C, P and the whole group B), and the second group consisted of fat-soluble vitamins-lipovitamins (A, D, E, K). However, as early as 1942-1943. academician A.V. Palladin synthesized the water-soluble analogue of vitamin K - vikasol. And recently water-soluble preparations of other vitamins of this group have been received. Thus, the division of vitamins into water- and fat-soluble vitamins to some extent loses its significance.