DISCOVERY AND SIGNIFICANCE OF VITAMINS^ 



By Sir Frex>ef.ick Gowland Hopkins, P. R. S. 

 Sir William Dunn Professor of Biochemistry, University of Cambridge 



Until the end of the first decade of the present century official 

 teaching concerning the nutritional needs of the human body was 

 still based on the results of classical studies by Carl Voit and Max 

 Rubner and on the views of the Munich School thence derived. The 

 adequacy of a dietary was measured in terms of calories and protein 

 alone. It was generally believed, alike by the academic physiologist 

 and by those concerned with practical dietaries, that questions of 

 palatability and digestibility apart, so long as the food of an indi- 

 vidual provided sufficient potential energy for the activities of his 

 internal organs and for the external mechanical work he might be 

 called upon to do, the only demand of a more specific kind made by 

 his body was for a certain, rather ill-defined, minimum of protein to 

 subserve the growth and maintenance of its tissues. Beside the 

 carbohydrates, fats, and proteins which provide these essentials, 

 natural foods were known, of course, to contain a variety of other 

 substances. These, however, are present individually in very small 

 amount, and except for certain minerals among them, necessary for 

 the formation of bone and for the maintenance of particular physical 

 conditions in the body, they were assumed to be without nutritional 

 importance. 



Facts, nevertheless, were already known which might well have 

 suggested that the body makes calls upon its food to supply needs 

 more subtle and more specific than those thus recognized. The his- 

 tory of scurvy, for example, and the clear demonstration made 

 already in the eighteenth century of the dramatic cure of that fell 

 disease which follows upon suitable, though relatively very small, 

 additions to an errant dietary, should, it would seem, have provided 

 a strong suggestion for the existence in certain foods of a substance 

 small in amount but with highly specific properties essential for the 

 support of normal nutrition; that is, for the existence of what we 

 now define as a vitamin. But, unfortunately, the views of the 



^ Reprinted by permission from Nature, vol. 135, no. 3418, May 4, 1935. 



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