382 INOSITOLS 



under many conditions intestinal synthesis of inositol is altered, and so 

 are the inositol requirements of the animal. There are also interrelationships 

 of nutrients, and thus the diet fed and its content of various nutrients may 

 influence inositol needs. It is also possible that there are substances, anti- 

 metabolites for example, in natural feeds which may have an effect on the 

 inositol needs of the animal. There undoubtedly are other possible explana- 

 tions. Regardless of which may be the right one, there is still no definite 

 postulate which can be regarded as established. Considerably more work 

 is needed to clear up the problem of the factors influencing inositol require- 

 ments of animals. 



Many investigators have used levels of 0.05 to 0.3 % of inositol in their 

 experimental rations. However, none of these levels are regarded as definite 

 requirements. 



Several investigators have studied the utilization of phytate P.^'^ Moll- 

 gaard and his associates have indicated the importance in the pig of the 

 intestinal pH and of the presence of phytase in the food. Woolley^ investi- 

 gated the ability of several substances to replace weso-inositol in the nutri- 

 tion of the mouse. Inositol hexaacetate, phytin, and soybean cephalin were 

 effective in curing alopecia in this series. In contrast, the strain of yeast 

 used was incapable of utilizing esters of inositol. Wiebelhaus et alJ found 

 the quantity of inositol absorbed from the intestinal tract of fasting rats 

 to be approximately a linear function of time and observed that the ab- 

 sorption of inositol monophosphate was more rapid than the absorption of 

 inositol, 



B. OF MAN 



A. T. MILHORAT 



Williams^ estimated that an average mixed diet of 2500 cal. contains 

 about 1 g. of inositol. Since evidences of inositol deficiency are not observed 

 on good mixed diets, the requirements of man cannot, under ordinary cir- 

 cumstances, exceed this amount. Williams concludes that 1 g. daily is a 

 "safe" level of intake but emphasizes that definite data are lacking. Ander- 

 son and Bosworth^ found that of 0.5 g. of inositol per kilo of body weight, 

 given by mouth, only 9 % was found in the urine, and none in the feces. 

 The inositol in the diet is predominantly from vegetable sources. How 



3H. M. Bruce and R. K. Callow, Biochem. J. 28, 517 (1934). 



* M. Gedroyc and S. Otolski, Arch. Chem. i Farm. 68, 106 (1936). 



5 H. MoUgaard, K. Lorenzen, I. G. Hansen, and P. E. Christensen, Biochem. J. 40, 



589 (1946). 

 6D. W. WooUey, /. Biol. Chem. 140, 461 (1941). 

 ^ V. D. Wiebelhaus, J. J. Betheil, and H. A. Lardy, Arch. Biochem. 13, 379 (1947). 



8 R. J. Williams, /. Am. Med. Assoc. 119, 1 (1942). 



9 R. J. Anderson and A. W. Bosworth, /. Biol. Chem. 25, 399 (1916). 



