384 ASCORBIC AaD 



in the early stages of depletion does not serve to protect the animal against 

 scurvy. Mannering^ states that "in view of the minimal ascorbic acid levels 

 found necessary for protection against scurvy, for reproduction, and for 

 prolonged survival, there is little to support the concept that saturation 

 with ascorbic acid is a prerequisite of adequate nutrition." 



(2) Alkaline Serum Phosphatase . Determination of the content and ac- 

 tivity of this enzyme has been suggested for evaluating the nutritional 

 status with respect to ascorbic acid. Gould and Schwachman^" showed that 

 the normal phosphatase content of guinea pig serum can be maintained 

 by a daily dose of only 0.225 mg. of the vitamin, suggesting a high degree 

 of sensitivity. 



(3) Content in White Blood Cells. Butler and Cushman^^ stated that the 

 level of ascorbic acid in the white cell-platelet layer in centrifuged blood 

 samples of human subjects constitutes the most accurate index of vitamin 

 C deficiency. The concentration in this layer may lie within the normal 

 range of 25 to 38 mg. per 100 g. of white blood cells, even with a low concen- 

 tration in the plasma. Crandon et alP found that the zero level in the 

 plasma of a human subject kept on a diet lacking ascorbic acid was reached 

 by the forty-first day whereas in the white cell layer the zero level was not 

 reached until the one hundred and twenty-fourth day. The leucocyte layer 

 was the last to become depleted and the first to become saturated when 

 ascorbic acid was supplied. Lowry et al.^^ studied the white cell and serum 

 vitamin C levels in three groups of normal young men maintained for a 

 period of 8 months on 8, 23, and 78 mg. of ascorbic acid per day, respec- 

 tively. When saturation tests were performed the increase in white cell 

 ascorbic acid concentration paralleled its retention. For this reason they 

 stated that the white cells "appear to be a valid index of the total body 

 concentration of ascorbic acid." Chevillard and Hamon^^ made a similar 

 study with guinea pigs and found that in animals deprived of ascorbic acid 

 the leucocyte-platelet layer showed decreases in the vitamin which closely 

 followed those of the body tissues. They found that the ascorbic acid value 

 of the leucocyte-platelet layer was about 30 mg. per 100 g. Values of less 

 than 20 mg. per 100 g. indicated advanced avitaminosis C. 



(4) Phagocytic Activity and Fragility of Polymorphonuclear Leucocytes. A 

 possible method for determining the requirement for combating infections 

 is suggested in the methods employed by Nungester and Ames.^* 



'» B. S. Gould and H. Schwachman, /. Biol. Chem. 151, 439 (1943). 

 31 A. M. Butler and M. Cushman, J. Clin. Invest. 19, 459 (1940). 

 , 32 J. H. Crandon, C. C. Lund, and D. B. Dill, Neiv Engl. J. Med. 223, 353 (1940). 

 " O. H. Lowry, O. A. Bessey, M. J. Brock, and J. A. Lopez, J. Biol. Chem. 166, 111 



(1946). 

 3^ L. Chevillard and F. Hamon, Compt. rend. soc. hiol. 137, 307 (1943). 

 3*W. J. Nungester and A. M. Ames, /. Infectious Diseases 83, 50 (1948). 



