A vitamin is a chemical compound that is needed in small amounts for the human body to work correctly. They include Vitamin A, many B vitamins (like B1, B2, B3, B6, and B12), Vitamin C, Vitamin D, Vitamin E, and Vitamin K. For example, citrus fruits such as oranges and lemons contain vitamin C.
Many vitamins can not be made by the body itself. The body needs to get them from other places, usually through food. A short term lack of a certain vitamin is usually not a problem, as the body is able to store vitamins for a short time. Not having a certain vitamin for a longer period of time can lead to different diseases, depending on the lacking vitamin. Probably the best-known of these diseases is scurvy, which results from not having enough Vitamin C.
Today, many drug companies make inexpensive pills that contain various vitamins. They help people avoid those diseases.
Currently there are no vitamins F to J. These existed at some time. Today they are no longer seen as vitamins. Some of them were also false leads, and turned out to be something else. Some were also renamed as B vitamins. Today, the B vitamins are a whole complex, and not just one vitamin.
The German-speaking scientists who isolated and described vitamin K (in addition to naming it as such) did so because the vitamin is intimately involved in the 'Koagulation' (clotting) of blood following wounding. At the time, most (but not all) of the letters from F through I were already designated, so the use of the letter K was considered quite reasonable. The following table lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex.
Previous name[1][2] | Chemical name[1][2] | Reason for name change[1] |
---|---|---|
Vitamin B4 | Adenine | No longer classified as a vitamin |
Vitamin B8 | Adenylic acid | No longer classified as a vitamin |
Vitamin F | Essential fatty acids | Needed in large quantities (does not fit the definition of a vitamin). |
Vitamin G | Riboflavin | Reclassified as Vitamin B2 |
Vitamin H | Biotin | Reclassified as Vitamin B7 |
Vitamin J | Catechol, Flavin | No longer classified as a vitamin |
Vitamin L1[3] | Anthranilic acid | No longer classified as a vitamin |
Vitamin L2[3] | Adenylthiomethylpentose | No longer classified as a vitamin |
Vitamin M | Folic acid | Reclassified as Vitamin B9 |
Vitamin O | Carnitine | No longer classified as a vitamin |
Vitamin P | Flavonoids | No longer classified as a vitamin |
Vitamin PP | Niacin | Reclassified as Vitamin B3 |
Vitamin U | S-Methylmethionine | No longer classified as a vitamin |