CHOLINE 



in man with a specific deficiency disease, this being frequently regarded 

 as one of the essential criteria of a vitamin. This argument is not 

 a very strong one, however, for as has already been pointed out several 

 other substances that are undoubtedly vitamins are not associated 

 with characteristic deficiency diseases in man. Actually, the existence 

 of a deficiency disease " in Nature " is largely fortuitous, due first, 

 to the existence of a foodstuff which either does not contain a substance 

 essential for human nutrition or from which such a substance has been 

 removed in some way and, secondly, the use of that foodstuff as a 

 staple or at least as a major article of diet. Clearly, the accidental 

 combination of these two factors would be less likely to occur with 

 substances, such as choline or inositol or for that matter amino acids, 

 which are present in virtually all foodstuffs and which are required in 

 relatively large amounts. In such instances, there is such a wide 

 margin between the amount normally present in foodstuffs and the 

 minimum amount necessary to support life that the worst that can 

 happen is a mild and often temporary deficiency state leading to vague 

 symptoms of ill-health. Acute symptoms would only be observed in 

 human volunteers maintained on diets from which the factor had been 

 deliberately, and more or less completely, removed. 



Another serious objection to the inclusion of choline in the vitamin 

 B complex is its inability to stimulate the growth of micro-organisms, 

 with one or two exceptions (page 596). It can hardly be regarded as a 

 member of the bios complex and in this respect differs sharply from 

 inositol, which it resembles in other ways. 



References to Section i 



1. A. Strecker, Annalen, 1862, 123, 353. 



2. N. F. Fisher, Amer. J. Physiol., 1924, 67, 634. 



3. F. N. Allan. D. J. Bowie, J. J. R. Macleod and W. L. Robinson, 



Brit. J. Exp. Path., 1924, 6, 75. 



4. J. M. Hershey, Amer. J. Physiol., 1930, 93, 657. 



5. C. H. Best and M. E. Huntsman, /. Physiol., 1932, 75, 405. 



6. C. H. Best and J. H. Ridout, ibid., 1933, 78, 415. 



7. C. H. Best, H. J. Channon and J. H. Ridout, ibid., 1934, 81, 



409. 



8. C. H. Best and M. E. Huntsman, ibid., 1935, 83, 255. 



9. B. Sure, /. Nutrition, 1940, 19, 71. 



10. P. Gyorgy and H. Goldblatt, /. Exp. Med., 1940, 72, i. 



11. V. du Vigneaud, /. Biol. Chem., 1939, 131, 57. 



12. W. H. Griffith and N. J. Wade, ibid., 567. 



13. D. M. Hegsted, R. C. Mills, C. A. Elvehjem and E. B. Hart, ibid., 



1941, 138, 459. 



14. W. H. Griffith and D. J. Mulford, /. Nutrition, 1941, 21, 633. 



