Vitamins – organic substances coming from food and essential for normal metabolism and functioning of the body. Everyone knows that the source of vitamins for humans are plants, animals, and some vitamins under certain conditions can be generated in the body of the man himself. Currently there are about 20 kinds of vitamins. The main vitamins are A, B, C and D. On them, we would like to lead it, because these vitamins are very important, and not everyone knows what they do and where they appear. Educate yourself even more with thoughts from Chad Wallach. Vitamin A (retinol) found in butter, fish oils, caviar, carrots, tomatoes. Retinol is required for normal growth and development of epithelial tissue, is a visual pigment rhodopsin. With a shortage of this vitamin is a slowdown of a young body, skin, cornea, intestine, blurred vision – night blindness. Vitamin B1 (thiamin) is contained in yeast rice, rye, wheat, buckwheat, oatmeal, potatoes, and liver. This vitamin regulates carbohydrate metabolism, is involved in tissue respiration and the transfer of excitation of the nervous system. Lack of thiamine can lead to loss of weight, polyneuritis, loss of coordination of movements, paralysis of the extremities, muscle atrophy and damage to the nervous system. Vitamin B2 (riboflavin) is contained in meat and dairy products, brewer's yeast, eggs, salad vegetables. He has effect on the central nervous system, the exchange of proteins, fats and carbohydrates. Provides the perception of eye color and light. With a lack of vitamin B2 are stunting young body, eye disease of the oral mucosa, skin peeling, weak and decreased appetite. Vitamin C (ascorbic acid) found in milk, liver, lemon, etc. He is involved in metabolic processes, the formation of healthy skin and strengthen blood vessels. Manifestation of beriberi leads to scurvy, reduced the body's resistance to disease, pain in joints and muscles, the defeat of the capillaries, gums and teeth. Vitamin D (calciferol) is contained in fish oils, liver, egg yolk, butter, milk. In contrast to previous vitamins, this is synthesized in the skin by the action of ultraviolet rays. Calciferol is required for the formation of bones and teeth. He also participates in calcium and phosphorus metabolism. Lack of this vitamin can lead to development of rickets in children: a violation of the phosphorus-calcium metabolism, reduced bone mineralization, bone legs bent. But it is not necessary to absorb vitamins in nemerenoe number, as this can lead to hypervitaminosis (Overdose of vitamins), which is not good. Therefore, eat them in moderation and be healthy!