RIBOFLAVINE 



nomial in twenty to sixty minutes. The injection increased the ribo- 

 flavine content of the infant's urine but did not increase that of the 

 placenta. 



The concentration of riboflavine in human milk averaged 17*3 /xg. 

 per 100 ml., 29 equivalent to 68-8 /xg. per day and, in the early stages 

 of lactation, was not affected by administration of riboflavine. During 

 the later stages, however, the amount secreted in the milk could be 

 substantially increased in this way. More recently, an average value 

 of 60 /xg. per 100 ml. has been reported. ^^" 



According to Roderuck et al.,^^ the riboflavine content of human 

 milk increased in the first ten days after parturition from o-oi to 0-45 

 mg. per day when the daily intake was 3-1 mg. The output in the 

 milk at this stage accounted for 3 to 32 % of the intake and the 

 urinary excretion for 12 to 82 %. The output in the mature milk 

 amounted to 3 to 15 % of the intake and the corresponding urinary 

 excretion to 26 to 61 %. The free riboflavine in the milk varied 

 from 43 to 86 % of the total. 



In France, the average riboflavine content of breast milk was foimd 

 to be 32-4 /xg. per 100 ml. in summer 1940 and 27-5 /xg. per 100 ml. 

 in the winter ; in 1942, the corresponding values were 23-3 and 20 -i 

 /xg. per 100 ml., corresponding to a decrease in the riboflavine intake. ^^ 



References to Section 11 



1. F. M. Strong, R. E. Feeney, B. Moore and H. T. Parsons, /. Biol. 



Chem., 1941, 137, 363. 



2. P. B. Pearson, M. K. Sheybani and H. Schmidt, Arch. Biochem., 



1944, 3, 467. 



3. H. F. Fraser, N. H. Topping and H. Isbell. U.S. Publ. Health 



Rep., 1940, 55, 280. 



4. J. W. Ferrebee, /. Clin. Invest., 1940, 19, 251. 



5. H. Isbell, J. G. Wooley and H. F. Fraser, U.S. Publ. Health Rep., 



1941, 56, 282. 



6. L. Laszt and L. D. Torre, Z. Vitaminforsch., 1943, 13, 77. 



7. M. Swaminathan, Indian J. Med. Res., 1942, 30, 37. 



8. P. B. Pearson and B. S. Schweigert, /. Nutrition, 1947, 34, 443. 



9. W. H. Sebrell, R. E. Butler, J. G. Wooley and H. Isbell, U.S. Publ. 



Health Rep., 1941, 56, 510. 



10. M. V. Davis, H. G. Oldham and L. J. Roberts, /. Nutrition, 1946, 



32, 143. 



11. W. Brewer, T. Porter, B. Ingalls and M. A. Ohlson, ibid., 583. 

 iia. S. E. Snyderman, K. C. Ketron, H. B. Burch, O. H. Lowry, O. A. 



Bessey, L. P. Guy and L. E. Holt, ibid., 1949, 39, 219. 

 116. J. N. Harris and F. I. Scoular, ibid., 1949, 38, 435. 



12. H. Oldham, E. Lounds and T. Porter, ibid., 1947, 34, 69. 



13. A. V. Trufanov, Biochimia, 1946, 11, 33. 



182 



