The discovery and subsequent naming of vitamins has its origins in the late 19the century and early 20th century. The first identification of what became known as vitamins occurred due to the research of Dr. Casmir Funk. Dr. Funk was attempting to find a means of treating the disease of beriberi through nutritional means. His research led to the understanding that many diseases had their origins in a lack of important nutrients, which he named vitamines. As more was understood about the nature of these vitamines, a need to develop a consistent means to assign names of vitamins became apparent.
The naming of vitamins began with simply assigning the next available letter of the English alphabet as the new vitamin was identified. Many vitamins, such as Vitamin A and Vitamin C, were simply assigned a letter in this manner. One notable exception is Vitamin K, which was first identified as part of research to deal with issues surrounding the coagulation of human blood. Discovered by German researchers, the designation of Vitamin K took place for two reasons. First, the designation of K was available at the time. Second, the designation tied in with the German word koagulation, making the use of K as the designation a common sense approach.
It is important to note that the common names of many vitamins may or may not be used. This due to the fact that the discovery of a vitamin sometimes occurred long before the scientific classification of the compound. In some instances, the chemical or scientific name for the vitamin is employed. Thus, the Vitamin B family is often identified by chemical names, and less often by the successive designations of B1, B2, etc. In some cases, vitamins were originally assigned a letter as part of the designation, but later moved to be included in the family of another vitamin. This is true of riboflavin, which was originally identified as Vitamin G, but later reclassified to B2, owing to its similarities with other B vitamins.
Today, there appears to be no new identification of vitamins with a name containing a single letter. More often, discovery and scientific classification take place in a short period of time and the vitamin is normally identified by the scientific name. While there is not much chance of adding more vitamins to the families for Vitamin D and Vitamin E, ongoing research continues to identify vitamins that aid in the healthy development and maintenance of the human body.