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VITAMINS, ANTIBIOTICS, 

 AND GROWTH 



Thomas H. Jukes 



AMERICAN CYANAMID COMPANY 



The vitamins are a small group of organic chemical substances with 

 special nutritional properties. Today we think so much along biochemi- 

 cal lines that it seems obsolete to classify substances in terms of their 

 relationship to nutrition. However, when we think in terms of evolution 

 and ecology, it is still very much to the point to consider the vitamins 

 as a separate biochemical family. 



The vitamins are best defined by the effects of their absence. The 

 omission of a vitamin from the diet of an appropriate test animal will 

 result in the appearance of a characteristic deficiency disease. In young 

 animals the disease is usually accompanied by a slowing of growth. 

 The deficiency can be alleviated by adding a suitable molecular form 

 of the missing substance to the diet. 



Another way of stating this is as follows: Animals are unable to 

 carry out biochemical reactions which are needed for the synthesis of 

 certain essential organic substances. Hence these substances, or their 

 precursors, must be supplied in the diet. Sometimes all that is needed 

 is a key fragment of the essential substance, or a molecule from which 

 the key fragment can be made in the body. If the fragment or its 

 precursor is not supplied in the diet, the chemistry of the body gets 

 out of order, and a vitamin-deficiency disease develops. 



One of the most interesting episodes in research is the story of the 

 vitamins. It was important from the standpoint of public health to dis- 

 cover and synthesize the vitamins. These substances then provided the 

 key to the understanding of a number of biochemical reactions. The 

 solution of a practical problem turned out to be important to the prog- 

 ress of knowledge. For example, folic acid, discovered to be a missing 



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