VITAMINS 349 



wilh subculaiicous breakage, edema, and joint pains. In children 

 these symptoms are accompanied by poor teeth and skeletal develop- 

 ment with characteristic bone changes. Wound healing is retarded, 

 and some investigators report an increased susceptibility to bacterial 

 invasion. Except for the anemia, these symptoms are attributed to 

 impaired formation of collagen and hyaluronic acid. These materials 

 are known to be important in the maintenance of teeth and the 

 skeleton and in the control of the permeability of tissues. 



Scmvy has become rather rare over most of the world with cases 

 seen only among persons with strong food prejudices, some remote 

 tribes, and infants fed bottled milk and without fruits and vegetables. 

 Formerly the disease was very common, especially among soldiers, 

 sailors, and travelers of all kinds. In 1780 there were 1,457 men 

 hospitalized with severe scurvy in a single British naval hospital. 

 Daily rations of lemon juice throughout the navy cut this rate to a 

 case each year in 1806 and 1807. Even though almost miraculous 

 cures date back to at least 1535 during Canadian explorations, out- 

 breaks of scurvy occurred through World War I in hospitals, asylums, 

 and prisons. The toll of human lives taken by scurvy cannot be 

 guessed at but is certainly huge. For example. Admiral Richard 

 Hawkins stated in 1593 that 10,000 English seamen had died of scurvy 

 within his own experience. During the voyage of Vasco da Gama 

 around the Cape of Good Hope in 1498, 100 men died of his crew 

 of 160. 



OTHER WATER-SOLUBLE FACTORS 



Choline 



Although not a typical vitamin, this substance is usually classified 

 with them for purposes of discussion. As might be guessed from the 

 structure, this substance plays a role in the metabolism of methyl 



(CH3)3NCH2CH20H 

 OH- 



choline 



groups (see pages 466 to 469). Choline occurs as a component of the 

 lecithins. It is also important in the functioning of the parasympa- 

 thetic nervous system, which depends in part on the presence of 

 acetylcholine for the transmission of nerve impulses. When the nerves 

 of this system are stimulated, they catalyze the formation of acetylcho- 

 line from choline and acetylcoenzyme A, using the enzyme choline 



