VITAMINS 201 



idea were the curing of scurvy by fresh fruits and vegetables (Lind 1757, 

 Budd 1841), the prevention of beriberi by using other foods in place of 

 polished (white) rice, and the demonstration by Eijkman (1897) that a 

 disease of fowls similar to human beriberi could be produced or pre- 

 vented at will by feeding the birds various diets. Eijkman thus intro- 

 duced the use of experimental animals as test subjects for such studies, 

 without which the modern development of the vitamin field would prob- 

 ably have been impossible. 



Funk (1912) was the first investigator to formulate and state clearly 

 the concept that each of the then known deficiency diseases was caused 

 by the absence from the diet of a separate definite chemical substance. 

 He had been trying to obtain in pure form from rice polishings the sub- 

 stance capable of preventing or curing beriberi, and since it appeared 

 to have the chemical properties of an amine, he proposed as a name for 

 all such essential substances the term "vitamine," a contraction of 'Vital 

 amine." 



At approximately the same time McCollum and other investigators 

 discovered that certain fats such as butter and cod-liver oil contained a 

 substance that in small amounts was capable of promoting the growth 

 of young rats and preventing the development of an eye disorder known 

 as xerophthalmia. Since the beriberi preventing substance was soluble 

 in water, McCollum concluded there were two "accessory dietary factors." 

 He designated the one "fat soluble A" and the other ''water soluble B." 

 Several years later (1920), when it had become evident that there were 

 at least three factors, two of which were in no way related to amines, 

 Drummond suggested that the terms of Funk and jNIcCollum be combined 

 by dropping the letter "e" from the word "vitamine" and adding the 

 letters A, B, and C to give the terms "vitamin A," "vitamin B," and 

 "vitamin C." As new vitamins have been discovered they have been 

 designated by letters added to the class name such as vitamin D, or by 

 use of subscript numbers, e.g., vitamin Bi, Bg, etc. 



The number of known vitamins has grown rapidly from the early 

 abbreviated list composed of vitamins A, B, and C to one comprising 

 some fifteen to twenty factors that apparently deserve to be included in 

 this category. Only those substances that have been generally accepted 

 by research workers in this field are considered in this brief treatment. 

 For convenience they may be classified as either fat-soluble or water- 

 soluble. In the former class belong A, D, E, and K, and in the latter, 

 ascorbic acid (or vitamin C) and the vitamin B group. This group 

 includes thiamine (vitamin Bi), riboflavin, nicotinic acid (or niacin), 

 pantothenic acid, pyridoxine (vitamin Be), biotin, pteroylglutamic acid 

 (abbreviated PGA; also called folic acid), vitamin B12 (antipernicious 

 anemia vitamin), choline, inositol, and para-aminobenzoic acid (PABA). 



Unfortunately, in the earlier work the experimental diets lacked more 

 than one vitamin with the result that symptoms ascribed to a deficiency 



