THE VITAMIN B COMPLEX 



As already stated, the existence of vitamin B^ or, as it is now 

 called in this country, aneurine or, in the U.S.A., thiamine, was first 

 demonstrated by feeding experiments on birds and human beings 

 suffering from a deficiency disease. The same method was used for 

 four other members of the vitamin B complex. The biological impor- 

 tance of nicotinic acid, for instance, was discovered as the result of 

 Goldberger's study of pellagra in negroes and " poor whites " in the 

 Southern States of the U.S.A. and his subsequent experiments on 

 humans and dogs. Ribofiavine was similarly identified as a vitamin 

 necessary for the growth of rats, pyridoxine as a factor that cured a 

 dermatitis in rats, and pantothenic acid as a factor that cured a 

 dermatitis in chicks. Up to this point, the isolation of the several 

 members of the vitamin B complex had followed an invariable routine 

 — first, the observation that an experimental animal developed 

 characteristic symptoms when maintained on a certain type of purified 

 diet, then the discovery that an extract of some foodstuff, more often 

 than not yeast or liver, would cure the symptoms, and finally attempts 

 to purify the factor using the deficient animal for following the progress 

 of the purification steps. With pantothenic acid, however, events 

 took a different course and one that had an important influence on 

 the subsequent history of vitamin science. 



It had been observed in 1901 by a Belgian microbiologist, 

 E. Wildiers, that certain yeasts failed to develop on a medium made 

 up of purified constituents, but that they grew satisfactorily when an 

 extract of yeast was added. He concluded that these organisms 

 required for their growth a factor derived from living cells, and he 

 gave this hypothetical factor the name " bios ". Many years later it 

 was shown that bios was not one single substance, but a mixture of 

 several substances. Various components were shown to be identical 

 with aneurine, ribofiavine, nicotinic acid and pyridoxine. Thus, the 

 substances that stimulated the growth of yeasts proved to be the same 

 as those that stimulated the growth of animals. In other words, the 

 bios complex and the vitamin B complex, if not actually identical with 

 one another, showed considerable overlap. One member of the bios 

 complex, not at that time identified with any member of the vitamin 

 B complex, was a substance to which the name pantothenic acid had 

 been given. Concentrates of this substance prepared from liver 

 showed chemical properties similar to those of the filtrate factor that 

 cured chick dermatitis, and an interchange of specimens by the 

 workers concerned showed that pantothenic acid cured dermatitis in 

 chicks, whilst the filtrate factor stimulated the growth of yeast. 

 Shortly afterwards the identity of the two substances was estab- 

 lished by degradation and S3mthesis. Here indeed was striking con- 

 firmation that the bios complex and the vitamin B complex had much 



