Introduction
Vitamins are organic substances that are vitally important. Earlier such substances included only proteins, fats and carbohydrates. Nowadays their number includes vitamins and mineral salts.
All the processes of the body related to the normal metabolism of substances occur with the participation of vitamins. They are part of more than 100 enzymes and catalyze a huge number of reactions in the body. Vitamins are involved in maintaining the body’s defenses, in increasing its resistance to various adverse factors. An important role in maintaining the body’s high resistance to disease has been established. Vitamins can weaken or even completely eliminate the side effects of antibiotics.
In modern conditions vitamins are used as an effective preventive measure against unwanted effects on the human body.
Providing the body with vitamins has complex forms and interrelationships.
Vitamin deficiency leads to the development of a kind of pathological conditions. Avitaminosis is possible only when the complete cessation of vitamin intake.
The intake of vitamins in the body may be insufficient as a result of improper cooking of food: heating, canning, smoking, drying, freezing – or due to irrational one-sided diet.
Vitamin discovery
The first conclusion about the existence of unknown substances, which are simply necessary for life, was made by a Russian doctor N.I. Lunin in 1880.
In his dissertation work performed at the University of Dorpat (now Tartu) he wrote:
“If, as the above-mentioned experiments teach, it is impossible to provide life with proteins, fats, sugar, salts and water, then it follows that milk, besides casein, fat, milk sugar and salts, contains other substances indispensable for nutrition. It is of great interest to investigate these substances and study their importance for nutrition. Experiments were conducted on mice.
Lunin’s conclusion was not recognized, even his supervisor G. Bunge was skeptical about the idea. The scientific world was in no hurry to recognize the existence of some unknown substances.
In 1889, the Dutch doctor H. Eikman discovered in chickens a disease similar to beri-beri and pelagra. It has been repeatedly suggested that these diseases are associated with malnutrition. But it is only possible to prove this through experiments on animals.
By 1910 sufficient material had been accumulated for the discovery of vitamins. And in 1911-1913 there was a breakthrough in this direction. In a very short time a large number of works on vitamins appeared.
The studies of the Polish biochemist Casimir Funk, who worked at the Lister Institute in London, played an important role in the development of vitaminology. In 1911, K. Funk made the first report on the isolation of a crystalline active substance from rice bran, which had therapeutic properties and quickly cured pigeons with polyneuritis. The scientist showed that the active substance is a simple nitrogen-containing organic base (amine). Its presence even in small quantities in the diet protects people and animals from beri-beri disease. Funk called the substance he discovered a “vitamin. Funk’s great merit is that he summarized the data on such diseases as beri-beri, scurvy, pellagra and rickets and stated that each disease is a lack of this substance. An article by C. Funk entitled “Etiology of Diseases of Deficiency” was published in June 1912. In 1914, he published a monograph entitled “Vitamins.
Subsequently, the science of vitamins has advanced dramatically. A considerable number of them have now been studied.
Classification of vitamins
Vitamin A (retinol) is involved in a number of redox processes and is therefore of great importance to the human body. Promotes child growth, increases the body’s resistance to infectious diseases. If the body lacks vitamin A, then develops hypovitaminosis, the first sign of which is night blindness, visual impairment at dusk. Lack of vitamin A also affects day vision, causing narrowing of the field of vision and disturbance of normal light sensation. The daily requirement for an adult is 1.5 mg, or 5000 IU. Vitamin A deficiency causes dry skin and hair, pallor, formation of boils, decreased appetite. Widely used vitamin A in medicine for the prevention and treatment of diseases such as dysentery, bronchitis, pneumonia, gastritis, hepatitis, and eye disease. A large amount, is contained and comes into the body with products of both animal and plant origin. It is found in fish liver, beef liver, milk, sour cream, butter, egg yolk. In plant foods contain pro-vitamin A-carotene, it is found in vegetables and greens: carrots, pumpkin, parsley, dill, tomatoes, green onions, red peppers, as well as fruits and berries. For better absorption of carotene these foods should be eaten with vegetable oil or sour cream.
Vitamin D is obtained by the body by synthesis in the skin during sun exposure and ingestion with food. The biological role of vitamin D is calcium and phosphorus metabolism, stimulates the metabolism of phosphoric acid necessary for the central nervous system. It is necessary for growth, for the work of the goiter, thyroid, parathyroid and sex glands.
Vitamin D is available in the liver of marine fish, butter, milk, egg yolk, fish roe.
With a lack of vitamin D in children develop rickets – a disease found among young children (two months to two years) in which the bones become soft. In an additional supply of vitamin D children need, as well as contingents of people who do not get enough ultraviolet rays – miners, subway workers living above the Arctic Circle, bed-ridden patients, etc.
Excess vitamin D promotes atherosclerosis, deposition of calcium in the internal organs.
Vitamin B1 (thiamine) was discovered in 1826 and synthesized in pure form only 10 years later. Thiamine is found in both plant and animal products. The best sources of thiamine are whole grains of various cereals, fruits of legumes, and nuts. Yeast and liver contain large amounts. It has a positive effect on the nervous and cardiovascular systems, the digestive organs.
The daily requirement for vitamin B1-2 mg if the body is deficient in vitamin B1 then develops a serious disease beri-beri.
Vitamin B2 (riboflavin) is involved in metabolism. An important property of its participation in the growth process, which increases the value and importance of the vitamin in the diet of children in early and adolescence. It also has a great effect on visual function, stimulates the formation of red blood cells, regulates the central nervous system.
The average human daily requirement is 2.5-3 mg.
Vitamin B2 is found in foods of plant and animal origin: eggs, cheese, milk, mushrooms, vegetables, fruits and yeast. Stable when foods are cooked.
Vitamin PP (nicotinic acid) is part of a number of enzyme systems in the body, normalizes blood cholesterol levels, gastric function, improves the secretion and composition of pancreatic juice, etc.
Nicotinic acid has the property to expand the lumen of capillaries and arterioles, as a result blood vessel spasms may disappear.
Widely present in foods of plant and animal origin: green peas, peas, beans, potatoes, cherries, grapes, plums, lamb, beef liver, eggs, yeast, etc.
Lack of vitamin PP in the diet leads to the severe disease pellagra. Patients experience pigmentation, scaling, and intestinal dysfunction.
The daily requirement for an adult is 15-20 mg.
Vitamin C (ascorbic acid) is one of the most important vitamins in the human diet. Its physiological importance in the human body is very diverse. It enhances the formation of hemoglobin and erythrocyte maturation, collagen formation, with its deficiency wounds heal for a long time. It also increases the body’s immunobiological resistance to infections and colds. Lack of vitamin C in the body can cause the development of scurvy. This inflamed gums, loose and fall out teeth develop anemia, bone and joint pain, and general dullness pale skin.
The daily requirement is 70-100 mg.
The human body does not produce vitamins, and therefore it is necessary that it comes with food. Very much of this vitamin in the green parts of plants, in many fruits and vegetables. Especially in the fruits of rose hips, black chokeberry, black currant, lemon, and the fruits of immature walnuts.
To conserve vitamin C during cooking should not allow prolonged cooking of food, food should be cooked with the lid closed, put the vegetables in boiling water or boiling broth, do not add soda.
