VITAMINS 223 



synthesized or the rapidity with which the synthesis is carried out may 

 not always be great enough to supply all the physiological needs of the 

 animal. This fact has been strikingly demonstrated by the discovery 

 that injections of vitamin C are of marked value in overcoming various 

 breeding difficulties of cattle that have long been a source of loss to the 

 dairy industry. 



Since the average human dietary is not likely to be completely lacking 

 in vitamin C, the symptoms of the earlier stages of scurvy, subacute or 

 latent scurvy as it has been termed, are of more significance to us. The 

 formation of intercellular substances which tend to acquire properties 

 resembling a gel seems to be under the influence of vitamin C. In the 

 absence of adequate amounts of the vitamin these intercellular substances, 

 which normally act as a cementing medium, are not formed properly or 

 may even be resorbed. Such changes may be observed microscopically 

 in connective tissue, bones, and teeth, and are beheved to occur in blood 

 vessels as well. Since the tooth changes are rather pronounced and readily 

 observed, a study of the extent of such changes offers a method for deter- 

 mining vitamin C. Hemorrhagic tendencies are noticeable even in sub- 

 acute scurvy. In fact, the "capillary resistance" test, which has been 

 devised to detect the beginning stages of scurvy, has as its basis the 

 resistance to development of hemorrhagic spots, through rupture of the 

 surface capillaries, when a tourniquet is used to produce intravascular 

 pressure. This condition and other symptoms of scurvy are shown in 

 Plate III, opposite p. 222. 



Prevalence of vitamin C deficiency 



Although scurvy in its worst form was quite prevalent in early explora- 

 tion days, its occurrence at the present time is rather limited. It is said 

 to be fairly common among the natives in South Africa, and certain tribes 

 of aborigines in central Australia are reported to suffer considerably 

 from it. The subacute form seems to be more prevalent than had been 

 suspected prior to development of the "capillary resistance" test. For 

 example, students in the university at Upsala, Sweden, showed a decreased 

 resistance to hemorrhage in the spring corresponding to a proportionate 

 decrease in vitamin C in the diet. The test has not been employed so 

 extensively in the United States. However, American investigators have 

 shown that administration of large quantities of vitamin C is beneficial 

 in promoting normal tooth formation in the growing child. Such results 

 suggest a probable deficiency in the diets of many American people. 

 Some experimental results even point to the probability that certain 

 rheumatic pains, particularly noticeable in late winter, may actually have 

 their origin in a lack of vitamin C. A rather interesting observation, 

 reported in 1939, was the marked improvement that vitamin C produced 

 in men suffering from lead poisoning. 



