572 THE TOCOPHEROLS 



assumption being that for some unknown reason a deficiency may have 

 existed, notwithstanding dietary abundance. There are numerous and more 

 recent statements both in support and in denial of this contention as ap- 

 phed to all farm animals. The problem is complicated by the fact that their 

 need of vitamin E for reproduction has not been clearly demonstrated;^^ 

 the young, through lack of enough E in their milk, suffer degeneration of 

 voluntary or cardiac muscle, from which they may or may not recover if 

 untreated. Tocopherol given to the young effects a cure. The dietary in- 

 adec^uacy in the dams can be due to the lack of green feed, the use of re- 

 stricted rations, degerminated cereals, or sophisticated concentrates. There 

 is increasing evidence that the responses of animals to tocopherol differ, 

 on the farm as well as in the laboratory .-°' -^ 



Many more experiments, carefully controlled and with guarded conclu- 

 sions, like those reported on swine,-^' ^^ must be performed before the re- 

 quirements of domestic animals are known. 



B. OF MAN 

 KARL E. MASON 



Requirements of tocopherol for man have not been satisfactorily estab- 

 lished and can be inferred in only an approximate manner on the basis of 

 what is known concerning dietary intake, effectiveness of absorption, rate 

 of utilization, extent of excretion, and tissue storage. An interesting dis- 

 cussion of the various factors operating between nature's deposition of to- 

 copherol in plant foods and the subsequent transfer of tocopherol across the 

 intestinal barrier in man has been presented by Hickman and Harris.^^ 

 It is reported that part of the dietary tocopherol is oxidized to quinones in 

 the intestine. ^^ Others,-^ who feel that there is very little destruction in the 

 intestine, indicate that perhaps more than half of ingested tocopherol may 

 be excreted in the feces. The measurement of fecal tocopherols is a difficult 

 procedure because of the presence of many interfering substances. Progress 

 has been made,^*- ^^-^^ and it is hoped that improved methods will make pos- 

 sible more informative tocopherol-balance studies. 



18 T. W. Gullickson, Ann. N. Y. Acad. Sci. 52, 256 (1949). 



20 J. K. Loosli, Ann. N. Y. Acad. Sci. 52, 243 (1949). 



21 D. B. Parrish, Ann. N. Y. Acad. Set. 52, 251 (1949). 



22 L. E. Carpenter and W. O. Lundberg, Ann. N. Y. Acad. Set. 52, 269 (1949). 



23 F. B. Adamstone, J. L. Krider, and M. F. James, Ann. N. Y. Acad. Sci. 52, 260 

 (1949). 



24 K. C. D. Hickman and P. L. Harris, Advances in Enzymol. 6, 469 (1946). 

 26H. Rosenkrantz, A. T. Milhorat, and M. Farber, /. Biol. Chem. 192, 9 (1951). 

 26 G. Klatskin and D. W. Molander, ./. Clin. Invest. 31, 159 (1952); /. Lab. Clin. Med. 



39, 802 (1952). 



