EFFECT ON VARIOUS PHYSIOLOGIC PROCESSES 673 



{6) Vitamin D in Relation to the Intestinal and Fecal pH 



A considerable amount of experimental evidence has been amassed 

 which indicates that a deficiency in vitamin D causes an increase of the 

 fecal and intestinal pH in a number of species. Zucker and Matzner^^s 

 reported that the pH of the feces of rats becomes higher when they be- 

 come rachitic, and that it reverts to the original le\-el when cod liver oil 

 is given. Similar results were obtained by Jephcott and Bacharach,'29 

 who found that cod Uver oil, irradiated cholesterol, and ultra\'iolet irradia- 

 tion reduced the fecal pH to the acid side. Heller and Caskey^'" observed 

 the same response to vitamin D supplements. 



A number of investigators^^^"^"^ hke^^ise noted a higher pH in the in- 

 testinal contents of rachitic rats than in normal controls. This phenom- 

 enon M'as apparently a general one, as it occurred throughout the small 

 and large intestine. After the administration of cod hver oil, or of \'ita- 

 min D itself, the pH of the intestinal contents decreased, i.e., the acidity 

 increased. Similar obser\'ations were made by Graj'zel and Miller-^^* 

 in the case of dogs, and by Khne and co-workers^^^ in chicks. 



However, the relationship between the changes in intestinal pH and the 

 cure of rickets is not clear. In the case of rachitic chicks, irradiation de- 

 creased the pH of the proximal portion of the intestines, but not that of 

 the distal portion. Shohl and Bing^^^ observed a change in the feces 

 from alkahne to acid when rats rendered rachitic bj^ diet were cured by 

 cod liver oil. However, this change did not occur in rats cured by irra- 

 diation of the food or by the administration of alkaline phosphates. Oser^" 

 is of the opinion that the effect of \dtamin D in increasing the pH of the 

 feces is unrehable and non-specific. Moreover, Jones^^^ reported that 

 increasing the acidity of the intestinal contents of rats by means other 

 than the administration of ^^tamin D did not result in a consistent or 



328 T. F. Zucker and M. J. Matzner, Proc. Soc. Exptl. Biol. Med., 21, 186-187 (1924). 



329 H. Jephcott and A. L. Bacharach, Biochem. J., 20, 1351-1355 (1926). 



330 V. G. Heller and C. Caskey, J. Nutrition, 2, 59-65 (1929-1930). 



331 E. M. Abrahamson and E. G. Miller, Jr., Proc. Soc. Exptl. Biol. Med., 22, 43S-439 

 (1924-1925). 



332 L. Yoder, /. Biol Chem., 74, 321-329 (1927). 



333 T. Redman, S. G. Willimott, and F. Wokes, Biochem. J., 21, 589-605 (1927). 



334 D. M. Gravzel and E. G. Miller, Jr., Proc. Soc. Exptl. Biol. Med., 24, 668-670 (1926- 

 1927). 



335 O. L. Kline, J. A. Keenan, C. A. Elvehjem, and E. B. Hart, ./. Biol. Chem., 98, 121- 

 131(1932). 



336 A. T. Shohl and F. C. Bing, J. Biol. Chem., 79, 269-274 (1928). 

 33V B. L. Oser, /. Biol. Chem., 80, 487-497 (1928). 



338 J. H. Jones, J. Biol. Chem., 142, 557-567 (1942). 



