518 VITAMIN Bi2 



Investigations by Hogan and Anderson*^ were made with a revision of 

 Hogan's purified diet^^ to include pteroylglutamic acid and increased 

 amounts of biotin. They conchided that the diet was sHghtly inadequate 

 for growth and seriously inadequate for lactation. They found^° that 

 growth was accelerated by the administration of anti-pernicious anemia 

 liver extract by intramuscular injection, but growth was not as rapid as 

 when the purified diet was replaced by cow's milk fortified with sucrose 

 and minerals. Vitamin B12 was used in an extension of the investigation,^^ 

 and it was found that growth was greatly increased by injection of the 

 vitamin. By a somewhat involved calculation, the authors estimated that 

 the quantitative requirement of vitamin B12 when administered orally was 

 0.26 7 daily per kilogram of live weight or not over 15 7 per kilogram of 

 food. 



An anemia in a single pig which responded to the injection of commercial 

 liver extract was described by Cartwright and coworkers. ^^ Four other pigs 

 receiving the same purified diet, except that commercial casein replaced 

 the vitamin-free product, showed no signs of deficiency. 



Purified diets were fed to young pigs by Neumann and coworkers. ^^ The 

 diets consisted of glucose, lard, minerals, vitamins, phthalylsulfathiazole, 

 and either "vitamin-free" casein or "alpha" (soybean) protein plus methi- 

 onine. This mixture was homogenized with water and fed to the pigs start- 

 ing at 2 days of age. The effects of concentrated anti -pernicious anemia 

 liver extract were studied, and the following results were obtained: 



Average daily gain during 8-week period, g. 



Improvements in the physical appearance of the pigs were noted in the 

 pigs receiving liver extract. Similar results were obtained in a subsequent 

 experiment with liver extract, ^^ and in addition the pigs responded to 

 vitamin B12, 2 7 injected daily, in the same manner as to liver extract. In 

 contrast, the pigs on the basal a-protein diet grew very slowly and three 

 died, all of which showed a loss of appetite, incoordination of the hind 



^9 A. G. Hogan and G. C. Anderson, J. Nutrition 36, 437 (1948). 



60 A. G. Hogan and G. C. Anderson, /. Animal Set. 9, 163 (1950). 



" G. C. Anderson and A. G. Hogan, /. Nutrition 40, 243 (1950). 



'2 G. E. Cartwright, M. M. Wintrobe, and S. Humphreys, /. Lab. Clin. Med. 31, 



423 (1946). 

 *' A. L. Neumann, J. Iv. Krider, and B. C. Joluison, J'roc. Soc. Exptl. Biol. i\fcd. 69, 



513 (1948). 

 '4 B. C. Johnson and A. L. Neumann, J. Biol. Chem. 178, 1001 (1949). 



