THE FOLIC ACID COMPLEX 



decrease in the faecal excretion, as it certainly should have done if 

 folic acid were being absorbed from the gut. 



Chicks also appear unable to utilise folic acid produced by synthesis 

 in the intestine, since the addition of succinylsulphathiazole to the diet 

 did not affect growth, feathering or haemoglobin formation.® 



References to Section 12 



1. G. J. Martin, Proc. Soc. Exp. Biol. Med., 1942, 51, 353. 



2. E. Nielsen and C. A. Elvehjem, /. Biol. Chem., 1942, 145, 713 ; 



B. Ransone and C. A. Elvehjem, ibid., 1943, 151, 109. 



3. F. S. Daft and W. H. Sebrell, U.S. Publ. Health Rep., 1943, 58, 



1542. 



4. C. W. Denko, W. E. Grundy. J. W. Porter, G. H. Berryman, T. E. 



Friedemann and J. B. Youmans, Arch. Biochem., 1946, 10, 33 ; 



C. W. Denko, W. E. Grundy, N. C. Wheeler, C. R. Henderson, 

 G. H. Berryman, T. E. Friedemann and J. B. Youmans, ibid., 

 1946, 11, 109. 



5. B. L. O'Dell and A. G. Hogan, /. Biol. Chem., 1943, 149, 323. 



6. L. D. Wright, H. R. Skeggs, A. D. Welch, K. L. Sprague and P. A. 



Mattis, /. Nutrition, 1945, 29, 289. 

 6a. R. E. Simpson, B. S. Schweigert and P. B. Pearson, Proc. Soc. 

 Exp. Biol. Med., 1949, 70, 611. 



7. W. E. Grundy, M. Freed, H. C. Johnson, C. R. Henderson and 



G. H, Berryman, Arch. Biochem., 1947, 15, 187. 



8. E. I. Robertson, L, J. Daniel, F. A. Farmer, L. C. Norris and G. F. 



Heuser, Proc. Soc. Exp. Biol. Med., 1946, 62, 97. 



13- HUMAN AND ANIMAL REQUIREMENTS OF FOLIC 



ACID 



Chicks 



Chickens required 10 //.g. per day of synthetic L. casei factor to 

 promote normal feathering and pigmentation caused by folic acid 

 deficiency.^ Five /ug. gave fair feathering but marked depigmentation, 

 and 2*5 /ng. were ineffective. 



According to Robertson et al.^ chicks required 25 jug. per 100 g. 

 of ration in order to survive up to six weeks of age, 45 /itg. per 100 g. 

 for growth and haemoglobin formation at four weeks, 45 /xg. per 100 g. 

 for growth at six weeks, 35 /xg. per 100 g. for haemoglobin formation 

 at six weeks, and not less than 55 /xg. per 100 g. for feathering at six 

 weeks. The addition of i to 2 % of sulphasuxidine did not affect 

 growth, feathering or haemoglobin formation. A diet containing 42 

 /xg. per 100 g. was adequate for ^gg production and hatchability.^o 

 and storage of pteroylglutamic acid did not take place below this 

 level. 26 



506 



