570 ■ the tocopherols 



6. General Comments 



Without reference to numerous other clinical reports, many of them un- 

 substantiated or unchallenged, dealing with beneficial effects of tocopherol 

 in a variety of other human ills, it will be apparent that the status of a-to- 

 copherol as a chemotherapeutic agent rests on an extensive but decidedly 

 controversial literature. Out of the array of conflicting evidence, there 

 seem to emerge indications that in certain disease processes there may occur 

 more or less local metabolic disturbances which may lead to increased 

 needs for, or even to local destruction of, tissue tocopherol, especially in- 

 volving the connective tissues and the related capillary bed; conceivably, 

 such local disturbances which may not be compensated for by normal body 

 stores of tocopherol can be overcome by high and sustained tocopherol 

 therapy. Whether this represents a glimmer of a pharmacologic action of 

 tocopherol, and whether functions of a-tocopherol other than its generally 

 accepted role as an intracellular antioxidant would be necessary to explain 

 such effects, remain for future research to decide. 



IX. Requirements and Factors Influencing Them 



HENRY A. MATTILL 



A. OF ANIMALS 



From what has been said, it is obvious that no categorical statements 

 can be made as to the recjuirements of different species or for the prevention 

 of a particular nutritional impairment in any of them. Even with a highly 

 purified basal diet, the results are subject to considerable biological varia- 

 tion, and with natural foodstuffs the minute variations implied in the ex- 

 perimental work described in the preceding pages can produce profound 

 effects, depending on the nature and history of each component. A diet 

 high in fat, particularly unsaturated fat, appears to increase the need for 

 vitamin E.^"^ Any statement regarding the MFD (mean fertility dose) 

 (0.75 mg. of a-tocopherol) for the rat holds only for the specific conditions 

 of the test. The daily needs of the two sexes are about equal, despite the 

 fact that the male requirement begins early (40th to 50th day of life), 

 whereas that of the female arises only after conception.^ The minimal daily 



1 H. Gottlieb, F. W. Quackenbush, and H. Steenbock, J. Nutrition 25, 433 (1943). 



2 G. A. Emerson and H. M. Evans, /. Nutrition 27, 469 (1944). 



^ H. Dam, H. Granados, and I. Prange, Acta Physiol. Scand. 18, 161 (1949). 



< H. M. Bruce, /. Hyg. 48, 171 (1950). 



5 K. E. Mason, Am. J. Physiol. 131, 268 (1940). 



