VH. I'JFFIOCTS OF DEFICIENCY 551 



petite and inipio\ed body growth in int'aiiLs I'ailing to i-espoud to otlicr 

 measures.""'' ''" These observations, based on a small number of subjects, 

 re(|uire confirmation. 



3. Vitamin E in Later Life 



As pointed out earlier, it seems rather unlikely that a natural deficiency 

 of A'itamin E ever occurs in man during adolescence or adulthood. On the 

 other hand, it is conceivaV)le that a "conditioned" deficiency might arise 

 as a result of (1) prolonged and severe impairment of fat absorption, (2) an 

 inherited defect of metabolism affecting the capacity of certain tissues or 

 organs properly to utilize the vitamin, or (3) certain types of metabolic 

 stress \\hich greatly increase requirements for the vitamin or its rate of loss 

 from tissue stores. 



There is no known symptomatology of avitaminosis E in man. Therefore, 

 any evaluation of the tocopherol status of man depends largely upon in- 

 formation pertaining to (1) dietary history, (2) plasma tocopherol levels, 

 (3) tocopherol concentration in tissues, and (4) the demonstration of histo- 

 pathologic changes which are comparable to those characterizing the ex- 

 perimental deficiency state in other primates and lower mammals. Dietary 

 histories are not particularly informative in the case of vitamins which are 

 stored rather tenaciously by tissues. Chemical and histopathologic analyses 

 of tissues and organs are limited to postmortem material or to small samples 

 obtained through biopsy. Blood levels represent the interplay of many 

 factors and are not necessarily indicative of the tocopherol status of the 

 individual as a whole; however, they constitute the most widely used cri- 

 terion for evaluating vitamin E nutriture in man. 



a. Plasma (or Serum) Tocopherols 



(1) Normal Levels. Most of our information on plasma tocopherols is 

 based upon blood samples analyzed by the method of Quaife and Har- 

 f-ig 192, 193 utilizing the Emmerie and Engel color reaction. A micromethod 

 later developed by Quaife et al}^'^ and requiring minute samples of blood 

 has been of particular value in studies with infants'^^' ^^'^ and will undoubt- 

 edly come into much wider use. The values given by these methods are 

 generally higher and more consistent in the hands of different investigators 

 than are those reported by European workers employing other chemical 

 procedures. 



"« J. Frey, Klin. Wochschr. 27, 348 (1949). 

 '" G. W. Schmidt, Arch. Kinderheilk. 138, 178 (1950). 

 1^2 M. L. Quaife and P. L. Harris, ./. Biol. Chem. 156, 499 (1944). 

 •" M. L. Quaife and R. Biehler, /. Biol. Chem. 159, 663 (1945). 

 >9i M. L. Quaife, N. S. Scrimshaw, and O. H. Lowry, J. Biol. Chem. 180, 1229 (1949). 

 '9* L. J. Filer, Jr., S. W. Wright, M. P. Manning, and K. E. Mason, Pediatrics 8, 328 

 (1951). 



