390 ASCORBIC ACID 



prevent scurvy and maintain| satisfactory health. Data to support these 

 statements are given in Tables XII and XIII. 



The level of intake which produces the maximum levels of as(;orbic acid 

 in the plasma and minimum loss in the urine is 100 mg. daily." Eighty mil- 

 ligrams daily will saturate tissues and maintain a high serum level. ^'^ 



Many factors increase requirements for ascorbic acid. Recovery from 

 scurvy seems to do this at least temporarily. Instead of 100 mg. per day, 

 which is required to maintain tissue saturation in the average person, at 

 least 200 mg. per day is required in the scorbutic subject after his tissues 

 have been saturated. Pregnancy, lactation, and thyrotoxicosis increase the 



TABLE XII 

 Excretion and Plasma Levels of Ascorbic Acid at Different Levels of Intake 



Intake, mg. Urinary excretion, mg. Amount retained, mg. Plasma level, mg. % 



50 11 39 0.85 



100 20 80 1.12 



200 109 91 1.14 



350 259 91 1.15 



TABLE XIII 

 Relationship of Intake of Ascorbic Acid to the Amount in the White Blood 



Cells and Serum 



Intake, mg. per day WBC ascorbic acid, mg. % Serum ascorbic acid, mg. % 



8 11.9 0.18 



23 12.9 0.20 



78 24.2 0.79 



amount of the vitamin utilized each day. Diarrheal states increase the loss 

 of vitamin in the stool, and achlorhydria decreases the amount of vitamin 

 absorbed before it is changed chemically to inactive substances. Rheumatic 

 fever, rheumatoid arthritis, acute and chronic infections, and situations 

 involving physical stress sidetrack the vitamin from the plasma to the 

 tissues or to storage depots. Increased metabolism stimulated liy these con- 

 ditions increases the need for the vitamin but not necessarily by the amount 

 which would be required to restore the plasma levels to normal. Cold at- 

 mosphere increases the excretion of ascorbic acid, but this vitamin does not 

 hasten adaptation to cold.''^ In general the same circumstance's which in- 



" E. P. Ralli, G. J. Friedman, and S. Sherry, Proc. Soc. Exptl. Biol. Med. 40, 604 



(1939). 

 '■• N. Glickman, R. W. Keeton, II. H. Mitchell, and M. K. Fahnestock, Am. J. 



Physiol. 146, 538 (1946). 



