Vitamins

substances which are irreplaceable components of our food. In itself

vitamins aren't a part of fabrics of an organism, aren't a power source. However vitamins are "activators" of many biochemical reactions providing a normal course of physiological processes of breath, blood circulation, digestion, immunity, growth, etc. Along with mineral substances vitamins belong to Micronutrients since they are required in the minimum doses.

arrive from the outside. From abundance of polyvitaminic complexes on

shelves of drugstores of an eye run up. How to choose the most suitable of them?

the first carry vitamins A, D, E, K.

Group B vitamins

are water-soluble: B1, B2, B5 (pantothenic acid), B6, B12, BC (folic acid), vitamins C, N (biooozes), RR (nicotinic acid).

A little from these vitamins (B1, B2, B6, B5, folic acid, vitamin K) are synthesized by normal microflora (bacteria) of intestines, however in very small quantity considerably conceding to daily requirement of a human body.

daily need for vitamins any, even well balanced, food can't.

The increase in the use of the refined, tinned products, culinary processing of the food, new methods of cultivation of fruit and vegetables in agriculture (processing of soils by insecticides, herbicides, introduction of mineral fertilizers, removal of genetically modified cultures, use of antibiotic preservatives for long storage of fruits) considerably reduce the content of vitamins B to food.

mineral substances it is necessary to use quite large number

of products in food. So, for example, for a covering of daily requirement for B1 vitamin it is necessary to eat not less than 1 kg of low-fat meat or 700 g of black bread to receive necessary 70 mg of ascorbic acid a day it is necessary to drink about 3 liters of apple juice. Certainly, it is impossible to use such quantity of food.

an arsenal of doctors is mono (containing only one vitamin)

and various polyvitaminic complexes. Usually monovitamin preparations are used at various diseases which treatment demands additional introduction of vitamins B the doses considerably exceeding usual daily requirement. For example, at psoriasis (the disease which main symptom is defeat of integuments) vitamin A is applied in the dose exceeding daily requirement by 10 times

an organism (for example, fat-soluble vitamins A, E)) the doctor

controls emergence of possible toxic effects them supervitaminosis : nausea, vomitings, belly-aches, fever, violation of work of a liver, kidneys of a peeling of skin and others.
Polyvitaminic complexes are used for prevention, and also for treatment of various forms hypovitaminosis – the states, being characterized sharp, but not full, as at avitaminosis, exhaustion of stocks of vitamin B an organism.

or partial deficiency of vitamins B an organism are usually

connected with various diseases, or specific states at which the balance between requirement and providing an organism with vitamins is broken.
Such imbalance diseases of a gastrointestinal path (gastritises, colitis, enteritis) can cause, worsening absorption and digestion of vitamins from food.
The need for vitamins also increases at heavy physical activity, adverse working conditions, in hot climate, in the conditions of Far North etc.
Observance of various unbalanced diets, starvation, reception of a number of medicines, the wrong storage and preparation of products belong to the external factors causing hypovitaminosis.

symptoms: increased fatigue, drowsiness, decrease in appetite, depression. However deficiency

of each vitamin can is shown also by a number of specific signs.

of each other. For example, folic acid and B12 vitamin

in common participate and strengthen effects of each other in processes of blood formation, synthesis of main "carriers" of a genetic material - RNA and DNA.
Synergistic (each other strengthening action) effect group B vitamins possess. B1 vitamin increases activity of ascorbic and nicotinic acids. At joint application toxic effects of fat-soluble vitamins A inclined to accumulation and decrease.
However opposite influence (antagonism) of various vitamins - also not a rarity. Antagonists are B1 and B6 vitamins of Routines (vitamin P) reduces activity thiamine (B1 vitamin) which, in turn, neutralizes action routine

to consider, what connections are its part.
So, for example,

for smaller irritation of a gastrointestinal path ascorbic acid is a part of polyvitamins in the form of salts – ascorbates. It is thus more preferable if the structure of a complex included a calcium ascorbate, instead of sodium. The increased use of sodium is undesirable at increase of arterial pressure, diseases of kidneys, violations of a water-salt exchange, is frequent - at pregnancy and a lactation. Deficiency of calcium is very widespread and many times over exceeds deficiency of sodium therefore use of an ascorbate of calcium helps to eliminate not only a vitamin C defect, but also calcium.

vitamins and with each other.
Zinc can prevent calcium absorption,

iron and molybdenum force out copper, manganese - magnesium. Copper competes with zinc and molybdenum. In addition, iron and copper oxidize vitamins A and E, weakening their action. Copper destroys ascorbic acid therefore their combination in one tablet is unsuccessful. On the other hand vitamin E improves selenium work, manganese improves absorption of vitamins A and With, and biooozes minimizes possible skin reactions at purpose of zinc.

30-60 minutes prior to food. They should be washed down

with water.
As appears from the name, fats are necessary for digestion of fat-soluble vitamins. Therefore absorption of vitamins A, D is most active, E and K occurs at reception of vitamin complexes during food or after food. Polyvitaminic complexes, as a rule, contain both water - and giros - soluble vitamins and are used for correction the poligipovitaminoznykh of states (a lack of several vitamins).
As absorption of water-soluble vitamins doesn't worsen at meal of water, as a rule, containing enough, polyvitaminic preparations are recommended to be accepted during food.

Ponomarev S. Yu. Terenin V. I.Khimiya. 10th class. Profile level.

M. Drofa, 2009;

The list of the used materials, Internet resources

alhimic.ucoz.ru/load/26-1-0-39
www.alleng.ru/edu/chem1.htm
www.uchportal.ru/load/60-1-0-9056