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Sources of vitamins. Kinds of vitamin status of organism. 4. Normal security vitamins in an organism. Artificial vitaminization of ready dishes and rules of its realization.
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Sources of vitamins
Vitamins are formed basically in plants, and also collect in an organism of animals. The person receives water-soluble vitamins with vegetative food, fat-soluble - with animal and vegetative food.
Some vitamins can be synthesized in organism of the person:
а) Vitamins group B, it is especial B 12, are formed in intestines at activity of microflora,
b) Calciferoles (vitamin D 3 - cholecalciferol) are formed in a skin at ultra-violet irradiation from provitamine - dehydrocholesterol.
c) Vitamin A (retynol)- from betta-carotines of vegetative food in very insignificant degree (1/6 part of requirement for vitamin A).
Kinds of vitamin status of organism.
By a level of vitamin security of organism allocate:
1. Avitaminosis - full absence of vitamin in a feed for a long time
2. Hypovitaminosis - insufficient receipt of vitamin in an organism (about 50 % of requirement)
3. Subhypovitaminosis - a boundary condition between hypovitaminosis and normal vitamin state
4. Normal security vitamins in an organism
5. Hypervitaminosis - superfluous receipt of vitamins (on vitamins A and D).
The avitaminosis and hypovitaminosis can be exogenic and endogenic (secondary - the caused infringement of absorbing of vitamins).
Methods diagnostics vitamin status:
а) By clinical picture, characteristic for each avitaminosis on concrete vitamin (scurvy, rickets, etc. ).
b) By Biochemical methods (content vitamines in blood or urine).
c) By Functional tests (skin haemorragies at vitamine-C hypovitaminosis).
Factors influencing at vitamins requirement of organism:
Exogenic:
- Phsycho-emotional and physical overstrain
- Work at high and low temperature
- Work in mines, on Far North
- At contact with industrial poisons, at reception medicines (antibiotics)
- At work with radiation, noise, vibration,
- Smoking
- Seasonal fluctuations - there are not enough vitamins in a diet in the winter and in the spring,
Endogenic:
- Age,
- Pregnancy and lactation
- Infectious diseases
- endocryn diseases - huperthireosis - strengthening metabolism in an organisme
- Intestinal diseases - infringement absorbtion vitamins
Artificial vitaminization of ready dishes and rules of its realization.
Sometimes there is deficiency of vitamins in nutrition, so it is necessary to do artificial vitaminization of food products. Artificial vitaminization of food products is obligatory in winter-spring period in hospitals, children establishments, social establishments (for old persons and invalids).
Rules of artificial vitaminization of food products.
Water-soluble vitamins put in juices and other water products, fat-soluble vitamins – in oil in dinner products.
Doze of vitamin in one portion of product must be equal daily need of vitamin.
After adding vitamin must be no thermal processing of product.
Value of separate vitamins.
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Vitamin C - ascorbinic acid. Per day it is necessary for the adult person 75-100 mg. Functions:
- Participates in oxidation-reduction processes,
- Strengthens a vascular wall - preventive haemorragia (scurvy),
- Stimulation immunity - resistancy to infections,
- Regulation exchange proteins and carbohydrates,
- Raises resistancy to toxic substances as antioxidizer,
- Influences mastering Са (at a scurvy at children - changes in bones).
Very unstable vitamin - an ascorbinic acid easily is oxidized.
Factors, destroying vitamin C: Temperature, Access of oxygen, Catalysts (salts of iron and cuprum - knifes, utensils), The alkaline environment, Enzyme ascorbinaza (activated at cutting vegetables and fruit. Inactivators of ascorbinaza - salt, sugar, vinegar).
Vitamin D - complex of calciferoles.
Distinguish ergocalciferol (vitamin D 2) - it is formed in plants and cholecalciferol (vitamin D 3) - is formed in a skin at action of ultra - violet from dehydrocholesterol. Biological activity has the products of their oxidation formed in a liver and kidneys. At lack of vitamin D at children - rickets, at adults - rarefication bones. Adjust absorbtion and exchange of Са - antirachitic action. It is especially important for children.
The reasons of D-hypovitaminosis: lack of a solar irradiation (Far North, pollution of the atmosphere, insufficient stay on fresh air, work in mines, etc. ), at a feed only by vegetative food.
Prevention and treatment of a rickets at children - introduction vitamin Dз - 500 International Units per day, preventive artificial UV irradiation (1/6 – 1/8 part of biodoze, at rickets – ½ - ¼ biodoze).
At taking very big doses of vitamin D – D-hypervitaminosis - heavy infringements of calcium exchange - calcinosis vessels of heart, kidneys etc. Calcinosis of coronary vessels in the childhood at taking big doses of vitamin D - predisposition to a heart attack of a myocardium.
Vitamin A - retynol. It is necessary for sight, growth, stimulation of immune system. The avitaminosis - is more often at children of preschool age - haemeralopia (night blindness) and kserophtalmya (degeneration eyes conjuctive and corneas). " Vitamin of prosperity " - contains basically in expensive animal products - cod-liver oil and a liver, is and in plants – betta- carotines. Per day - 1, 5 - 2 mg.
Attributes A-hypervitaminosis: a headache, grow bald, infringements in a bone fabric and in a liver, at pregnant - spontaneous abortions and uglinesses of a fruit. The reason – taking big doses of vitamin-A preparations, less often - consumption of a liver of a polar bear - a fatal retinol poisoning.
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