On vitamins also high temperature and light (UV radiation), oxygen from atmosphere and acidic conditions (adding calcium hydrogen carbonate), metals or acids act adversely.
Also it is possible to recognize situations of excess of vitamins – hypervitaminosis from OD and not justified use of very high doses of multivitamins.

The 13 well-known vitamins are divided according to the ability of absorption in fats or in water into two categories:
- fat-soluble vitamins – A, D, E, K (are generally consumed with food, which contains fats and because they can be stored in fat in organism, we do not have to consume them every day)
- water-soluble vitamins – vitamins from group B, C (they can not be stored in organism and that’s why need to consume them regularly

HISTORY OF VITAMINS


About the existence of vitamins has not been known for a long time. The vitamins were invented between the end of 19th century and the beginning of 20th century, when the researchers recognized the essential nutrients (proteins, fats, glycids) and mineral substances and thought that they are only ingredients of our diet.

They fed the experimental animals with these known substances in pure conditions. On their surprise, these animals did not grow well and after time they sickened and died. We know, for example, the experiments that made the Russian scholar N. I. Lunin; in the year 1881 he fed one group of mice with natural fresh food and another one only with pure basic nutrients. After a little time appeared that mice fed with natural food are in better situation than the other. So Lunin supposed that in fresh eatables are some still unknown substances, which are necessary and essential for life. He figured out that just these substances has to get every being in order to do not feel sick or even from its deficiency die. So Lunin became the creator of first scientific idea about the existence of substances, which we call today vitamins.

But his report about the results of experiments was forgotten; so in common, the discoverer of vitamins was the Polish Kazimír Funk. Almost 30 years later (1912) after Lunin Funk found out that one of these unknown substances is the organic compound of amine character. He isolated it from the peel of rice and called it vitamin (from Latin words vita – life and amin – the compound of nitrogen). In the history of discovery of vitamins also the Holland doctor Christian Eijkman became famous, that he found out that Japanese mariners, who ate mainly peeled rice suffered from deficiency of vitamin B and that caused the disease beriberi. This discovery markedly changed the opinion on correct content of healthy nutrition, because to that time it was expected that the base of healthy nutrition are proteins.

The individual vitamins were discovered step by step with the accretion of scientific knowledge and so the science has expanded from limited beginnings to the extensive science – vitaminology. Today, there are published so many scientific works about vitamins that the scientists not sufficed to read them. They are not interested in the discoveries of new vitamins, but they explain the attendance of known vitamins in metabolism, study the results at taking vitamins like medicine and suchlike.