Vitamins are organic compounds that the organism does not need as energy sources, but for other vital functions, which, however, the metabolism cannot synthesize to meet demand. Vitamins must be taken in with food, they are essential substances. Plants do not need vitamins, they can synthesize all the organic substances they need themselves. Vitamins are divided into fat-soluble and water-soluble vitamins.
Chemically, the vitamins do not form a uniform group of substances. Since the vitamins are quite complex organic molecules, they do not occur in inanimate nature. Vitamins must first be produced by plants, bacteria or animals. In different animals, different substances are sometimes considered vitamins.
For example, most animals can produce vitamin C themselves instead of having to take it in with their food. Dry nose primates, which include humans, some families in the order of bats and passerines, all bony fish and guinea pigs cannot do this because they lack the enzyme L-gulonolactone oxidase. Cats also need retinol, but occupy a special position because, unlike almost all other animals, β-carotene cannot be converted into retinol. Of these, 11 cannot be synthesized in any way by the organism itself. multivitamin
Cholecalciferol can be produced by the body itself, provided there is sufficient sun exposure. Self-synthesis also exists for niacin, which can be produced from the amino acid tryptophan. The necessary intake of niacin depends on the amount of protein added and is thus influenced by dietary habits. Examples are vitamin A and vitamin C, a carboxylic acid.
The trivial names use letters, sometimes combined with a number. In some cases there have been or are several trivial names, but as a rule only one trivial name has prevailed in each case.