112 



INANITION AND MALNUTRITION 



The effects of deficiency in vitamins A and B upon the growth curves of young 

 rats are shown in Fig. 45. 



When young animals are placed on diets deficient in vitamin A, there is a 

 variable latent period during which growth continues (though at a retarded 

 rate), probably by the aid of the vitamin stored in the fats and lipoids of the 

 body. Evans and Bishop ('22) found that the body storage of vitamin A in 

 young rats is apparently exhausted in 4-100 days. Osborne and Mendel 

 ('21) hold that for growth of rats vitamin A is much less important than vitamin 

 B; and especially for nutrition in adults (Mendel '20). Shipley, Park, 

 McCollum and Simmonds ('21) found that in young rats on diets deficient in 

 phosphorus and vitamin A, the arrested growth was resumed upon the addition 

 of vitamin A (see also Fig. 45). Korenchevsky ('23) found that diets deficient 

 in vitamin A, or calcium, or both, when fed to the male rat only, have no 



200 



"•••••# , 



*1 month-* 



au 



*i¥ 



x***** 



Fig. 45. — Chart showing growth curves of young rats fed on diet deficient in both vitamins 

 A and B. The curves represented by dots (....) show the inability of the rats to grow when 

 both vitamins, A and B, are absent from the diet. When A alone is added, e.g., in butter fat, 



(curves marked ), there is no improvement; but upon adding both A and B (curves marked 



), excellent growth follows. When vitamin B alone is added, there is sometimes 



slight growth (curves marked xxxx), probably due to unexhausted reserve stores of A, but 

 growth failure eventually follows. (Drummond; Med. Res. Comm. '19.) 



apparent effect on the offspring. When such diets are fed to the pregnant 

 female, still-births are more frequent. Even though the newborn may appear 

 normal, they are unusually susceptible to rachitoid disorders later, especially 

 when the deficient diet of the mother is continued during lactation. 



The relation of vitamin A to the cause of rickets was mentioned above in 

 connection with mineral deficiencies. The characteristic ocular lesions (xeroph- 

 thalmia) produced by deficiency of vitamin A will be discussed in Chapter XIII. 



Vitamin B. Polyneuritis and Beriberi. — The importance of vitamin B in the 

 production of polyneuritis in animals (especially birds) and of human beriberi 

 became evident through the work of Eijkman ('97) and numerous later investi- 

 gators. For review of various other theories of beriberi, see Vedder ('13, '23) 

 and Vaughan ('23). Nagayo ('23) claims that human beriberi, although it 

 may involve a deficiency of vitamin B as one factor, is a disorder distinct from 

 experimental polyneuritis and more closely resembles the infantile "Mehlnahr- 

 schaden." The marked atrophy of the body in experimental polyneuritis 

 does not occur in human beriberi. The failure of growth in young animals on 

 diets deficient in vitamin B was demonstrated by Funk and Macallum ('15), 

 Osborne and Mendel ('17a), Abderhalden ('19) and Shipley, McCollum and 



