INTRODUCTION 



inadvertently changed from polished rice, on which the prisoners were 

 fed, to unmilled rice the paralysed hens recovered. This suggested to 

 him that beriberi was in some way connected with food and not with 

 infection. Forthwith, Eijkman began to experiment, and found that 

 he could induce paralysis in hens by feeding them on polished rice and 

 could then cure the paralysis by adding rice polishings to their diet. 

 His colleague, Grijns, subsequently showed that beans also prevented 

 paralysis in birds, and that an extract of beans or rice polishings cured 

 both paralysed birds and beriberi patients. The factor thus shown 

 to be present in these materials was later known as vitamin B. Thus 

 a fourth dietary essential — vitamins— was added to the three elements 

 — carbohydrate, fat and protein — recognised by the nineteenth- 

 century nutritionists. The miain materials for building this particular 

 " edifice of human knowledge " were now available, but the story of 

 how it is being erected — for it is not yet finished — is a long and com- 

 plicated one. It has been built, like any other house, brick by brick 

 and plank by plank. Sometimes progress has been rapid and one 

 individual or, more often, a team of workers has contributed several 

 courses to the brickwork. Sometimes, indeed, the building has 

 assumed a distinctly lop-sided appearance with one wing completed 

 almost before the foundations of another have been laid. 



This book is concerned with only one aspect of the story of nutri- 

 tion, and does not even set out to tell the story of all the vitamins, 

 but only the story of those water-soluble vitamins which we now call 

 the vitamin B complex. Progress in this field has been so rapid, and 

 so much information has accumulated in recent years, that a complete 

 review of all that is known about the vitamins would fill more than 

 one volume. Besides, the story of the vitamin B complex is a coherent 

 one and the pattern which it follows gains in clarity when this group 

 of vitamins is considered apart from the other factors of nutritional 

 importance. This review of the vitamin B complex is an attempt, in 

 the words of the quotation at the heading of this chapter, " to stand 

 back and survey what has been built and how it has been done ", 

 even though the building is still surrounded by scaffolding and the 

 workers are still actively engaged in completing various parts of it. 



Recent research has made it more and more evident that the 

 members of the vitamin B complex, although chemically diverse, 

 constitute a group of biologically related substances, responsible for 

 effecting transformations of fundamental importance to the life of 

 organisms ranging in complexity from men to bacteria. They are, in 

 fact, some of the building blocks around which the fabric of all living 

 structiures is built. It is to emphasise this one-ness of function that 

 a book dealing with the vitamin B complex alone appeared to be 

 desirable. 



