INTRODUCTION 



633 



Table 3 (Continued) 



Tissue 



Animal 



Provitamin D, 



parts per 1000 



total sterol 



3.9 



2.3 



1.8 



1.8 



1.5 



1.2 



0.80 



0.70 



0.70 



0.50 



0.50 



0.45 



0.40 



0.32 



0.30 



0.30 



0.25 



0.25 



0.10 







° Adapted from W. H. Sebrell, Jr., and R. S. Harris, The Vitamins, Academic Press, 

 Inc., New York, 1954, Volume II, pp. 149, 150. 



(PenicilUum spp.), yeasts and lichens. ^''^■^°^ According to Savard and 

 Grant, ^"^ ergosterol can be prepared from clay mold {PeniciUium notatum). 

 Although considerable amomits of ergosterol are present in PeniciUium, 

 this mold has not become a commercial source, since the yields are quite 

 low. The most practical source of ergosterol is dried yeast, in which the 

 provitamin makes up 90 to 100% of the total sterols. ^"^ Strains of brewery 

 yeast (Saccharomyces cerevisiae), grown in aerated wort, serve for this pur- 

 pose. 



Although the main sources of ergosterol are the Cryptogams, there are well 

 authenticated reports that its presence has been observed in animals. Thus, 

 Windaus^^ and Bock and Wetter^"^ reported that ergosterol comprises up to 

 25% of the total sterols of the red road snail {Avion empiricorium) , and ap- 



ws C. E. Bills, Physiol. Revs., 15, 1-97 (1935). 

 '0^ C. Tanret, Ann. chim. phys. [8], 15, 313-330 (1908). 

 los K. Savard and G. A. Grant, Science, 104, 459-460 (1946). 



'"^ H. R. Rosenberg, Chemistry and Physiology of the Vitamins, Interscience, New York, 

 1945. 



10" F. Bock and F. Wetter, Z. physiol. Chem., 256, 33-41 (1938). 



