692 



PANTOTHENIC ACID 



-1 +1 



Log of body weight, kilos 



Fig. 11. Pantothenic acid requirement of the mouse, the rat, and the dog, in 

 milligrams per kilogram of body weight. (Prepared by M. E. Dumm.) 



per kilogram of body weight (at the beginning of the experiment) is shown 

 with reference to the log of the body weight in kilograms for the three 

 species on which quantitative data are available. In general, the data sug- 

 gest that the requirement for pantothenic acid, expressed per kilogram of 

 body weight, is greater for small mammals than for large ones, and that 

 within a given species the requirement may be considerably greater for the 

 young animal than for the adult. 



Although the estimation of the human requirement on the basis of in- 

 formation obtained from other species is notably uncertain, the data in Fig. 

 11 might be interpreted as suggesting that the human rec^uirement is prob- 

 ably less than 0.1 mg. per kilogram, or no more than 6 to 8 mg. daily for 

 adults. 



4. Toxicity of Pantothenic Acid 



In discussing pantothenic acid intake and requirement, it seems reason- 

 able to mention briefly what is known of the toxicity of this vitamin. 



The toxicity of pantothenic acid was studied by Unna and Greslin^^ in 

 mice, rats, dogs, and monkeys. Very large doses, up to 1 g. per kilogram 

 in monkeys and 50 mg. per kilogram in dogs, seemed to have no toxic 

 effect. The author and associates^"- ^^ have administered from 10 to 20 g. 



" K. Unna and J. Greslin, Proc. Soc. Exptl. Biol. Med. 45, 311 (1940). 



80 H. Gershberg, S. H. Rubin, and E. P. Ralh, J. Nutrition 39, 107 (1949). 



81 H. Gershberg and W. J. Kuhl, Jr., J. Clin. Invest. 29, 1625 (1950). 



