Vitamins (part-1)

What are?
Vitamins are relatively simple organic compounds that, although they only appear in smallest amounts, are essential for the life. The animal, generally, are not able to synthesize them they do or it in insufficient amounts, reason why they must obtenerfas from foods, sometimes like vitamins, that is to say, molecules that the metabolism of the animal transforms later into vitamins. Some exceptions exist, like the vitamin C, that is necessary in the humans, but is synthesized by the majority of the animal from glucose. Vitamins are component coenzymes or of coenzymes. The animal require certain daily amounts of each vitamin and any alteration in these amounts can produce upheavals in the metabolic processes. These upheavals can be: vitamin deficiency, if there is a total deficiency of a vitamin; hipovitaminosis, if the deficiency is partial; and hipervitaminosis, if an excess of a vitamin exists.

Vitamins are present in foods in smallest amounts compared to the macro-nutrients, proteins, carbohydrates and fats. The adult average in the industrialized countries infers around 600 grams of dry weight in food to the day, of which less than 1g is vitamins.

A unique food does not exist that contains all the vitamins, therefore a diet balanced and varied for a suitable ingestion is needed. Each one of the thirteen vitamins that are known nowadays own a specific function in the organism, that makes unique and irreplaceable. Vitamins because they are essential for the life. Of thirteen vitamins, four are liposoluble: vitamin To, D, and K. The rest are water soluble: vitamin C and vitamins of the complex B, B1, B2, B6, B12, folic acid, biotin, pantothenic acid and niacin.

History
The history of vitamins can be divided in five periods:

1) The empirical treatment of some diseases by means of hundreds of foods. Nowadays, these diseases are recognized like vitamin deficiency. An example is the use of the liver to deal with the nocturnal blindness (deficiency vitamin A), by the Egyptians (Papyrus Ebers 1550-1570 AC), Chinese, Japanese, Greek, Roman, Persian and Arab Syrians. Another example is the treatment of escorbuto (vitamin deficiency C) with the extract of pine needles (Indian North Americans) and with citruses (European of century XVII).

2) The second period around 1890, was characterized by the ability to induce diseases by deficiencies, as the beriberi, took to the concept of which small amounts of "accessory factors of growth" are necessary for the growth and the life, and to the term "vitamine", given by the Funk scientist in 1912.

3) The third period was characterized by seven decades of investigations, arriving itself at the discovery, isolation, structuring and synthesis of all the vitamins, finalized with the syntheses of the B12 vitamin in 1972. The majority of the scientists thinks that the discovery of some new vitamin is improbable, although they are continued the efforts in this sense. Many of the investigators of this "time of gold" of vitamins received the Nobel prize in recognition to the obtained profits, among them, Sir Frederick Hopkins, call the "father of vitamins".

4) A fourth period started during the establishment of the biochemical functions, the dietarios requirements and the commercial production. In 1930, for example, I reach the conclusion that the B2 vitamin (riboflavin) was part of an enzyme, this finding took to determine the roll of vitamins of the complex B like coenzymes. The first commercial synthesis of vitamin C was the realised one by Reichstein in 1933, being the principle of a successful industrial effort that took to the vitamin availability relatively little expensive for the investigation, and the use of fortificantes of foods and for supplements. With the flour fortification, cereals and other foods, the diseases by specific vitamin deficiencies such as escorbuto, beriberi, raquitismo and pelagra are branches in developed countries. But in Africa, Asia and Latin America the chronic diseases related to the diet continue being a problem for the public Health. In these countries the necessity exists to eliminate the frank deficiencies by vitamin, C and Vitamins of the complex B, like thus also deficiencies by other micro-nutrients (Iodine, iron, selenium, Zinc and calcium). In any case, still in countries highly industrialized numerous nutritional evaluations of the population they indicate that the marginal vitamin deficiency is still frequent. They are difficult to detect and mainly ignored, it exists today in vitamins is related to an increased risk to develop chronic diseases.

5) The increasing number of works on the benefits beyond the prevention of deficiencies and the new biochemical functions of vitamins has given rise to a fifth period that began in 1955 with the report that the niacin owned an effect in the reduction of the cholesterol. This effect nowadays is well accepted, not having anything to do with the classic coenzyme roll, knowing a clearly effect on the health, besides the prevention of the classic enfermdedad by him deficiency, that is pelagra. From this it completes observation, a great amount of epidemiological works has suggested rich the vitamin food consumption antioxidants, vitamin C, and E, ß-carotene, reduces the risk of suffering certain chronic diseases, such as certain types of cancer, cardiovascular diseases and cataracts. The investigators suggested free radical them of I oxygenate, highly reactive and potentially harmful they contribute to the development of these diseases when attacking the cellular membranes, the nucleic proteins and acids. Vitamins antioxidants are part of the natural defenses against the free radicals of I oxygenate. Institutes of world-wide reputation estan generally investigating the precise roll of vitamins and antioxidanes in particular in mantenimiendo of a optimum health.

Finally, the work in the knowledge of the biochemical function of vitamins in you complete two decades has expanded in considerable form our concepts of how they work in our organism and they adudan to give a chemical base for obsercaciones "in alive" of his effects on the health. Vitamins continue fascinating and in the center of renewed attention on the part of the investigators, of the professionals of the health of the nutrition, of goburnamentales beings, as well as of I publish generally.