FACTORS ALTERING CONCENTRATION OF CAROTENOIDS 509 



min A, in the case of normal children or of those with folliculosis, respec- 

 tively. During the active phase of pneumonia, both carotene and vitamin 

 A are reduced in the plasma 944 ; they return to normal values on convales- 

 cence. Reduced values for serum vitamin A are found in rheumatic pa- 

 tients. 945 On the other hand, no changes in the provitamin A levels in the 

 blood occur in nephrosis. 946 However, after the feeding of vitamin A 

 alcohol, higher values were obtained, indicating that, in the nephrotic 

 syndrome, the liver does not store vitamin A as rapidly as in normal in- 

 dividuals. In the case of patients with severe renal failure, Johns et al. 9tl 

 found little change in serum vitamin A, in spite of the fact that the patients 

 were depleting the liver vitamin A by excreting as much as 1000 I.U. daily 

 in the urine. Huszak and Ger6b 948 listed the vitamin A and carotene con- 

 tent of blood serum in various diseases of the nervous system. 



(2) Tocopherols {Vitamins E) 



a. Normal Values for Plasma Tocopherols. According to Ames and 

 Harris, 949 the normal concentration of tocopherol in blood plasma ranges 

 from 0.9 to 1.2 milligram per cent, although extreme variations of from 

 0.1 to 3.0 milligram per cent have been noted in some cases. Lemley and 

 co-workers 950 reported a mean serum tocopherol level of 1.09 ± 0.17 milli- 

 gram per cent in twenty-one young healthy adults, while Klatskin and 

 Krehl 951 cited an average of 1.23 milligram per cent for their twenty- 

 three normal adults. The value recorded by Darby et a/. 952 is 1.06 ± 0.06 

 milligram per cent. Engel 953 found that tocopherol levels in normal adults 

 receiving 15 mg. of vitamin E daily approximated 0.8 milligram per cent. 

 Levels as high as 1 2 milligram per cent were seldom observed, and did not 

 occur in the case of patients receiving 120 mg. of vitamin E daily. The 

 earlier figures of Varangot et aZ. 954 for plasma vitamin E, i.e., 0.19 milligram 



944 H. W. Josephs, Am. J. Diseases Children, 65, 712-727 (1943). 



945 R. E. Shank, A. F. Coburn, L. V. Moore, and C. L. Hoagland, J. Clin. Invest., 23, 

 289-295(1944). 



946 B. M. Kagan, E. M. Thomas, D. A. Jordan, and A. F. Abt, J. Clin. Invest., 29, 

 141-145(1950). 



947 R. Johns, H. Hoch, and J. R. Marrack, Biochem. J., 41, liii (1947). 



948 S. Huszak and T. Ger6b, Z. Vitaminforsch., 19, 330-335 (1947). 



949 S. R. Ames and P. L. Harris, Intern. Rev. Vitamin Research, 22, 26-34 (1950). 



950 J. M. Lemley, R. G. Gale, R. H. Furman, M. E. Cherrington, W. J. Darby, and 

 G. R. Meneely, Am. Heart J., 37, 1029-1034 (1949). 



951 G. Klatskin and W. A. Krehl, J. Clin. Invest., 29, 1528-1541 (1930). 



952 W. J. Darby, M. E. Cherrington, and J. M. Ruffin, Proc. Soc. Exptl. Biol. Med., 63, 

 310-312(1946). 



953 C. Engel, Ann. New York Acad. Sci., 52, 292-299 (1949). 



954 J. Varangot, H. Chailly, and N. Rieux, Compt. rend. soc. biol, 137, 210-211 (1943). 



