VITAMINS Bg, B4 AND Eg 



4. S. G. Smith, H. Hawfield, R. Curry, R. Connar and J. Collins, 



/. Elisha Mitchell Sci. Soc, 1943, 59, 117. 



5. P. J. Fonts, /. Nutrition, 1943, 25, 217. 



6. D. V. Frost and F. P. Dann, ibid., 1944, 27, 355. 



6a. A. E. Schaefer, C. K. Whitehair and C. A. Elvehjem, ibid., 1948, 

 35, 147 ; A. E. Schaefer, S. B. Tove, C. K. Whitehair and C. A. 

 Elvehjem, ibid., 157. 



7. W. C. Russell, A. E. Teeri and K. Unna, ibid., 1948, 35, 321. 



8. M. B. Gillis, G. F. Heuser and L. C. Norris, ibid., 1942, 23, 153. 



9. M. Rubin and H. R. Bird, /. Biol. Chem., 1946, 163, 387, 393. 

 10. H. R. Street, /. Nutrition, 1944, 28, 395. 



3. VITAMINS 63,64 and B5 

 Vitamins B3 and B5 



Vitamin Bg is the name given to a factor present in yeast which, 

 according to R. R. Williams and R. E. Waterman,^ was necessary to 

 restore to normal the weight of pigeons maintained on a vitamin B 

 complex-deficient diet, after the polyneuritic symptoms had been 

 cured by administration of vitamin Bj ; it was unstable to heat. 

 L. Randoin and R. Lecoq ^ had earlier reported the existence of a 

 similar factor destroyed by alkaline autoclaving. 



Evidence for the existence of a third alkali-labile factor in addition 

 to vitamins B^ and Bg was obtained by Carter et al.,^ who found that 

 a fraction from liver, alleged to contain this factor, vitamin B5, cured 

 heart block in pigeons fed on polished rice ; they also found that 

 large amounts of vitamin B^ did not fully restore the weight of pigeons, 

 thus apparently confirming the existence of vitamin Bg. Vitamin Bg 

 was shown to be necessary for the chick as well as for the pigeon by 

 Eddy et al.^ 



Further support for the existence of vitamin Bg was provided by 

 J. R. O'Brien ^ who, like Carter et al., showed that a vitamin B^ con- 

 centrate administered at a level equivalent to forty times the anti- 

 neuritic dose failed to restore fully the weight of pigeons fed a diet of 

 autoclaved polished rice. An alcoholic extract of wheat or yeast was 

 effective in restoring the weight to normal and an extract made after 

 acid hydrolysis was still more effective, but an aqueous extract was 

 quite inactive. J. R. O'Brien confirmed the instability of vitamin Bg, 

 not only to heat, but also on storage or exposure to air. 



The first note of doubt regarding the bona fides of vitamin Bg was 

 struck by C. W. Carter,^ who observed that the weight of pigeons 

 was fully restored when caseinogen was added to the diet, suggesting 

 that the so-called vitamin Bg deficiency was due to an inadequate 

 intake of protein. The cardiac arrythmia previously attributed to 



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