THE REACTION TO FOOD 337 



controlled dietary regimen are accepted as a qualitative test for 

 vitamin a. 



The term "vitamin b" now designates the principle discovered 

 by Eijkman which is the etiological agent in beri-beri. When this 

 substance is lacking from the diet the motor nerve cells in the 

 cord are damaged and peripheral neuritis followed by atrophy of 

 those groups of muscles whose motor nerves are injured develops. 



In vitamin c deficiency the walls of the capillary vessels of the 

 vascular system are especially injured, but it is not known with 

 certainty whether the endothelial cells suffer the principal damage 

 or whether the cement substance holding them together is 

 destroyed. Certain it is that hemorrhage due to rupture of the 

 capillaries is the most striking feature of scurvy but resolution of 

 bone substance is also quite marked. 



Vitamin d is concerned with the deposition of calcium and 

 phosphorus in the bones. It regulates in some way the concen- 

 tration of phosphorus and to a lesser degree the calcium of the 

 blood. In the absence of vitamin d the amount of phosphorus falls 

 to a surprisingly low level so that the soIubiHty product of calcium 

 X phosphorus is not great enough to permit of the precipitation 

 of tricalcium phosphate for deposition in the osseous system. 



Vitamin e functions in some manner not yet understood. 

 Sterihty is produced alike in males and females by a deficiency 

 of this principle but the manifestation of a deficiency of vitamin e 

 in the two sexes differs considerably. In males atrophy of the 

 germinal epithelium and consequent loss of the power of spermato- 

 genesis is seen. In females ovulation tends to remain normal but 

 death of the young in prenatal life and their resorption constitutes 

 the mode of termination of an incomplete gestation. 



Vitamin f, originally called by Goldberger p-p to designate its 

 pellagra-preventive properties, is now believed to be the etiological 

 agent in pellagra. According to such data as exist, a deficiency of 

 this principle promotes the development of changes in the skin 

 which result in a characteristic erythemia, bronzing, injury to the 

 mucosa of the mouth and digestive tract, chronic diarrhea and 

 the nervous symptoms characteristic of that disease. 



Vitamin a is found abundantly in fish liver oils, fats from 

 mammalian livers, butter fat, egg yolk, yellow pigmented 

 vegetables and leaves of plants generally. It is absent or 

 nearly so from vegetable foods of all kinds, white varieties 

 of fruits and vegetables and in fact all fruits and vegetables 

 not containing yellow pigments. Thus, red beets, red and 



