NUTRITION AND GROWTH 619 



Investigation of the distribution of the vitamines among the various 

 foodstuffs, and their degree of stability towards heating, etc., has been 

 very materially facilitated by the fact that certain of the lower animals 

 suffer diseases like those seen in man when vitamines are absent from 

 the diet. This renders it possible to prosecute the investigations in- 

 tensively and under scientifically controlled conditions, thus affording 

 knowledge which enables us to alleviate human suffering. 



The Antiberiberi or Antineuritic Vitamine, Beriberi is a disease char- 

 acterized by wasting, anesthesia and paralysis, and sometimes by ex- 

 cessive edema. Pathologically, it is a form of severe neuritis. It is 

 common in rice-eating communities, and the first clue to its precise cause 

 was afforded by the observation that it does not occur among people 

 who take unmilled rice, and that it disappears in those who take "pol- 

 ished" rice when the millings or a watery extract of them (pericarp and 

 germ) are added to the diet. It was observed by Eijkman that the poul- 

 try of a prison where beriberi was prevalent exhibited symptoms very 

 like those of the human disease, and further investigation showed ex- 

 tensive nerve degeneration to exist in the affected animals. Pigeons 

 fed on polished rice develop exactly the same symptoms so that experi- 

 mental investigation soon rendered it possible to determine with accu- 

 racy which foodstuffs prevent beriberi, and the further properties of 

 the active substance. 



Meanwhile McCollum and Davis discovered that the absence of the 

 same water-soluble vitamine interfered seriously with the growth of 

 young animals. This is shown in Curve II of Fig. 186, from the observa- 

 tions of Hopkins and Chick, which is constructed on the same principles 

 as those of Fig. 184. It will be observed that the withdrawal of the 

 vitamine caused an immediate cessation of growth followed by the pe- 

 riod during which the body weight remained more or less constant, but 

 ultimately declined. During this stage muscular incoordination is a 

 prominent symptom, and death ultimately occurs. The curves show 

 that this vitamine must disappear from the organism when it is with- 

 drawn from the food and that the animal cannot synthetize it. 



The table on page 623 shows the distribution of the water-soluble 

 vitamine in the commoner foodstuffs. It will be noted particularly that 

 it is present in abundance in the seeds of plants and the eggs of animals. 

 It is very plentiful in yeast and in yeast extracts, which may there- 

 fore be added to the diet when there is risk of its deficiency. It is 

 absent from bread made with white wheat flour, but beriberi is rare in 

 people living on this food, since other foodstuffs containing the vitamine 

 are usually also taken. Beriberi is unknown where rye bread is the 

 staple food. 



The Antirachitic Vitamine (Fat-soluble A Factor). The first inkling 



