380 ASCORBIC ACID 



from a level of 3 to 5 % to one of 20 to 75 %}'' These data do not justify 

 mixing ascorbic acid with inorganic ferrous salts for oral use, since absorp- 

 tion of pure ferrous iron is so excellent. 



Because plasma ascorbic acid levels are low in rheumatoid arthritis'^ 

 and in rheumatic fever,^^ this vitamin has been used for many years in the 

 treatment of these diseases without any definite proof of effectiveness. 

 Recently it has been recommended again, this time with desoxycorticos- 

 terone in rheumatoid arthritis, in an attempt to gain a relatively inexpen- 

 sive cortisone effect.^" There is no proof that this combination has any 

 beneficial effect.^^ So far, scurvy and subclinical ascorbic acid deficiency 

 are the only conditions affecting human beings in which ascorbic acid has a 

 specific therapeutic effect. Prevention of scurvy, the megaloblastic anemia 

 of infancy, and possibly iron deficiency anemia are the only known pro- 

 phylactic effects. 



XI. Requirements 



A. OF ANIMALS 



MARY ELIZABETH REID 



1. Criteria for Judging Requirements 



The vitamin C requirements of the guinea pig have been reviewed by 

 Mannering.^ As he points out, the requirements should be \-iewed in re- 

 lation to the function under consideration. The requirements may differ 

 for growth, for maintenance of adult animals at different ages, and for 

 reproduction, pregnancy, and lactation. Other factors such as temperature, 

 rate and mode of administration of the vitamin, type of diet, and infection 

 and trauma may also influence the need. Various macroscopic and micro- 

 scopic characteristics may be used in evaluating the requirements. Macro- 

 scopic measurements of the vitamin C status may be made by determining 

 the increase in weight of the whole animal, the growth of certain organs 

 such as the teeth and/or adrenals, the blood levels with respect to plasma 

 or white cell concentration of the vitamin, and the level of alkaline serum 

 phosphatase. Microscopic measurements are based on changes in the teeth 



27 C. V. Moore and R. Dubach, Trans. Assoc. Am. Physicians 64, 245 (1951). 



28 J. F. Rinehart, L. D. Greenberg, and F. Baker, Proc. Soc. Exptl. Biol. Med. 35, 

 347 (1936). 



29 J. F. Rinehart, L. D. Greenberg. and A. U. Christie, Proc. Soc. Exptl. Biol. 

 Med. 35, 350 (1936). 



^" E. Lewin and E. Wassen, Lancet II, 993 (1949). 

 »i J. H. Kellgren, Lancet II, 1108 (1949). 

 * G. J. Mannering, Vitamins and Hormones 7, 201 (1949). 



