IX. OCCURRENCE 



541 



IX. Occurrence 



J. M. HUNDLEY 



There is a tremendous volume of literature which presents in detail the 

 nicotinic acid content of practically every form of living matter or sub- 

 stances derived from living matter (Table XIII). Much of this information 

 is of but limited value, from the standpoint of practical nutrition, since we 

 know that there are many factors which influence the amount of nicotinic 



TABLE XIII 

 Occurrence of Nicotinic Acid in Organisms of Various Biological Phyla 



(from Woods et al}) 

 (7/g. of moist tissue) 



Frog (Rana) 



Horned toad 



Snake (Thamnophis) 



Red ant (Dolichederus) 



Cockroach iPenplaneta americanus) 



Termites (Zootermposis) 



Drosophila virilis larvae NY 



Drosophila virilis Larvae NO 



Oyster (Mytilus) 



Earthworm (Lumbricus terrestris) 



Protozoa (Tetrahymena geleii) 



Aerobacter aerogenes, aerobic 



Serratia marcescens 



Pseudomonas fluorescens 



Clostridium butylicum, anaerobic 



Mushroom (Coprinus atranentarius) 



Mold 



acid that can be derived from a given diet, factors which cannot be readily 

 assessed quantitatively except by actual experiment. The amount of tryp- 

 tophan in relation to the balance of other amino acids, the type and amount 

 of carbohydrate, the amount of fat, the relative availability of the nicotinic 

 acid in the food, and the possibility of intestinal microbial synthesis all 

 influence the pellagra-preventive potency of a given diet. For this reason 

 the data on the pellagra-preventive potency of foods, gathered by Gold- 

 berger and his associates by actual test on pellagrins and on blacktongue 

 dogs, still are reliable for practical use.''''^ The potencies (good, fair, and 



1 A. M. Woods, J. Taylor, M. J. Hofer, G. A. Johnson, R. L. Lane, and J. R. McMa- 

 han, Univ. Texas Publ. 4237, 84 (1942). 



i"* J. Goldberger and W. F. Tanner, Public Health Repts. (U. S.) 39, 87 (1924). 



2 J. Goldberger, G. A. Wheeler, R. D. Lillie, and L. M. Rogers, Public Health Repts. 

 {U. S.) 41, 297 (1926). 



