DIGESTION AND ABSORPTION 697 



COW, Harris et al}^ noted that ^dtamin E supplementation increased milk 

 fat concentration (27%) and total milk production (21%), but that it did 

 not result in an augmented \dtamin E excretion into the milk. 



4. The Digestion and Absorption of the Tocopherols 



When the tocopherols are given, even in moderate doses, their absorption 

 is quite inefficient. Juhasz-Schaffer''^'' proved that definite amounts of 

 this \itamin are lost in the feces. After feeding C^'* -tagged tocopherol in 

 oil solution to rats, Shantz^"^ could account for an absorption of only 20%, 

 the remainder being excreted via the intestine. Simon, Gross, and Mil- 

 horat'"^ reported that, when rabbits were given 10 to 15 mg. of C'-' -labeled 

 (/-a-tocopheryl succinate orally, about 74% could be recovered from the 

 feces in three days, and as much as 80% after six days. Engel and Heins^"^ 

 recorded a coefficient of digestibility of 60 for \dtamin E from wheat germ 

 oil, and a figure of only 13 when the source of the vitamin was dried grass. 

 Pindborgi"^ was of the opinion that a biosynthesis of vitamin E occurs in 

 the intestine, but Harris^"^ opposes this ^^ew and beheves that the fecal 

 vitamin E merely represents undigested tocopherol from the ingested food. 

 The relatively low tocopherol content of muscles, body fat, and blood 

 of rats suggests either that the absorption is very inefficient, or that the 

 vitamin may be destroyed in the gastrointestinal tract, or both. It may 

 also be considered to be the result of a rapid destruction within the body, 

 or ma}' be attributed to an inefficient capacity for storage. ^°'"'' Dju and 

 co-workers^ '' observed that, when a high level of a-tocopherol was given to 

 domestic hens, large amounts of unchanged tocopherol were excreted in the 

 feces. Klatskin and Molander'^-'^^^ found that, in the case of healthy 

 men on average diets, fecal excretion accounted for about two-thirds of the 

 calculated dietary intake. However, it is not knowm how much of the 



1"^ A. Juhdsz-Schaffer, Virchoic's Arch. path. Anat. u. Physiol, 281, 53-65 (19.31). 



"* E. M. Shantz, Unpublished data cited bv P. L. Harris, Ann. Rev. Biochem., 18, 391- 

 394(1949), p. 410. 



los E. J. Simon, C. S. Gross, and A. T. Milhorat, J. Biol. Chem., 221, 797-805 (1956). 



'»«» E. J. Simon, A. Eisengart, L. Sundheim, and A. T. Milhorat, /. Biol. Chem., 221, 

 807-817 (1956). 



'"' C. Engel and J. T. Heins, Acta Brevia Neerland. Physiol. Pharmacol. Microbiol., 13, 

 37 (1943). 



108 J. J. Pindborg, Nature 164, 493 (1949). 



"•9 P. L. Harris, Nature, 165, 572 (1950). 



"0 T. Moore and K. R. Rajagopal, Biochem. J., 34, 335-342 (1940). 



"1 M. Y. Dju, M. L. Quaife, and P. L. Harris, Am. J. Physiol., 160, 259-263 (1950). 



112 G. Klatskin and D. W. Molander, ./. Clin. Invest., 31, 159-170 (1952). 



•i" G. Klatskin and D. W. Molander, /. Lab. Clin. Med., 39, 802-814 (1952). 



