DISTRIBUTION OF B VITAMINS 19 



as long ago as 1889 7 and was found to be without physiological effect. It 

 was found to be excreted unchanged in later experiments. 8 Only after its 

 physiological functioning was suspected 9 has its widespread natural occur- 

 rence been established. 



Evidence for Universal Biological Occurrence of B Vitamins 



The universal presence of each B vitamin in living cells is indicated by 

 microbiological evidence which will be discussed in later paragraphs. 

 Before this method of study became so generally applicable, it was 

 realized, for example, that thiamine occurs widely. Williams and Spies* 

 list in tabular form about 90 different types of products which contain 

 thiamine. These include animal tissues, fish, dairy products, legumes, 

 cereals, vegetables, fruits, nuts and yeast. The quantitative information 

 given by them is based entirely upon animal experiments. 



In early investigations involving riboflavin, it was found in yeast, kid- 

 ney, liver, suprarenals, corpus luteum, egg yolk, egg white, milk, urine, 

 blood serum and the retinas of fish eyes. 10 Advantage was taken in this 

 case of the fact that riboflavin exhibits characteristic fluorescence. Its 

 fluorimetric determination will be discussed later. For most of the evidence 

 bearing on .the universal distribution of the B vitamins in general, how- 

 ever, we must depend on microbiological evidence. 



The first evidence as to the universal occurrence in living matter of 

 what is now a recognized B vitamin was obtained in connection with 

 pantothenic acid. 11 A systematic study based upon a microbiological test 

 was presented in 1933, which indicated that the same acid growth deter- 

 minant was present in all types of living organisms. The materials exam- 

 ined represented eleven different biological phyla: Chordata, Arthropoda, 

 Echinodermata, Mollusca, Annulata, Plathylminthes, Mxyomycetes, Bac- 

 teria, Fungi, Algae and Spermatophytes, and in the case of the more 

 common phyla several examples were tested. Because of the evidence for 

 its diverse distribution, this substance was named pantothenic acid (from 

 the Greek, meaning from everywhere) . It should be noted by contrast 

 that the seemingly diverse sources of inositol and choline mentioned above 

 on page 18 represent in each case only three phyla. Likewise, the 

 evidence for the widespread occurrence of thiamine based upon animal 

 tests above and the requirements of some insects involved not more 

 than four phyla: Chordata, Arthropoda, Fungi, and Spermatophytes. It 

 may be mentioned at this point, though the question will be discussed 

 later, that ascorbic acid, which is not considered a B vitamin, is widely 

 present in the tissues of about seven phyla, yet it is not present, to the 



* Williams, R. R. and Spies, T. D., "Vitamin Bi (Thiamin) and Its Use in Medi- 

 cine," The Macmillan Co., New York, N. Y., 1939, 411 pp. 



