The word “vitamin” goes back to a Polish biochemist named Casimir Funk, which was created in 1912 during intensive research into the vitamin deficiency disease beri-beri. Casimir Funk constructed the term “vitamin” from “vita”, which means life and “amine”, since the isolated compound was an amine, i.e. a nitrogenous compound. However, it later became apparent that there are also nitrogen-free compounds which, despite this, belong to the group of vitamins.
Vitamins do not provide humans with energy such as food, but they are essential to life because they are essential for the functioning of metabolic processes. Since our body is not able to produce vitamins itself, our organism must be supplied with precursors of vitamins or the vitamins themselves through food. Preliminary stages of vitamins are called provitamins.
These are still inactive and are only converted into an active form in our body by transformation. Each vitamin has two different names. Vitamins can be named according to their chemical structure.
However, they can also be distinguished from each other by means of a letter and a number. There are 20 different vitamins, 13 of which are indispensable. Vitamins are divided into two groups according to their solubility: water-soluble (hydrophilic) vitamins and fat-soluble (lipophilic) vitamins.
This differentiation also makes it possible to determine whether the vitamin can be stored in our organism or whether this is not possible and the vitamin must be supplied continuously. The water-soluble vitamins cannot be stored in the organism, which means that they must always be taken in. An exceptional case is vitamin B12 (cobalamin), which can be stored in the liver despite its water solubility.
In contrast to the water-soluble vitamins, the fat-soluble vitamins can be stored well in the organism. As a result, an excessive intake of lipophilic vitamins can lead to hypervitaminosis. Hypervitaminosis is a disease that is caused by an unusually high intake of vitamins.
The absorption of the fat-soluble vitamins in the small intestine depends on the bile acids. If there is a lack of bile acids, the absorption of fat and also of fat-soluble vitamins from the intestine is restricted. A lack of bile acids can occur in the context of liver disease, such as cirrhosis of the liver, or after a resection, i.e. removal of the terminal ileum, where the bile acids are normally absorbed back into the body.