IX. EFFECTS OF DEFICIENCY IN HUMAN BEINGS 363 



The le^Tl in the white cell-platelet layer (the bulTy coat), normally 25 to 

 38 mg. per 100 g., reaches zero after 121 days of deprivation at approxi- 

 mately the same time that scorbutic lesions appear. It is of the greatest 

 diagnostic significance. 



4. Saturation and Tolerance Tests 



Experience at the Cincinnati General Hospital indicates that persons 

 with clinical scurvy will not have any ascorbic acid demonstrable in the 

 plasma until 1800 to 2000 mg. of this substance have l)een administered by 

 mouth in divided doses of 100 mg. five times a day. The plasma is drawn 

 each morning before the first dose of ascorbic acid. This is essentially a 

 plasma tolerance test. Other similar tolerance tests have been used pre- 

 viousl3^ Kadji et al. introduced the concept of the ascorbic acid index. -^ 

 This index is 100 times the product of the fasting plasma ascorbic acid 

 value and the increase in plasma ascorbic acid 4 hours after intramuscular 

 injection of 200 mg. of the vitamin in infants or 500 mg. in children or 

 adults. They report that in active scurvy the index is below 0.8. In persons 

 with very deficient reserves the index is between 0.9 and 6.0. In normally 

 saturated subjects the index is over 10. Unfortunatelj^, most patients with 

 severely depleted ascorbic acid reserves have plasma ascorbic acid levels of 

 mg. %. Methods for ascorbic acid are not accurate between zero and 

 0.1 mg. %. Therefore, such patients will have indices of zero whether they 

 have scurvy or not, and the index is no more significant than the fasting 

 plasma level. 



Saturation tests which depend upon changes in the urine and plasma 

 ascorbic acid levels after an appropriate test dose have been used more 

 commonly. Such saturation tests have employed the following techniques: 



1. ]Measurement of the 24-hour urinary excretion of ascorbic acid after 

 the oral administration of a standard test dose (5 mg. per pound of body 

 weight) .-^ 



2. The administration of a standard oral dose of ascorbic acid (15 mg. per 

 kilogram of bod}^ weight), and the determination of the blood plasma and 

 urinary ascorbic acid each hour for 5 hours with the patient in a fasting 

 state. '^- -^ In severely depleted or scorbutic patients, the plasma level rises 

 to about 0.4 mg. % and falls rapidly back toward zero. The urine shows 

 little if any ascorbic acid. 



3. The measurement of the rate of plasma ascorbic acid drop and urinary 

 excretion in 5 hours following the intravenous administration of a test 

 dose of 1 g. of ascorbic acid to adult patients.-^ 



" L. Kadji, J. Light, and C. Kadji, J. Pediat. 15, 197 (1939). 



*»M. A. Abbasy, L. J. Harris, S. N. Ray, and J. R. Marraoh, Lancet II, 1399 (1935). 



" J. F. Rinehart and L. D. Greenberg, Ann. Internal Med. 17, 672 (1942). 



" I. S. Wright, A. Lilienfeld, and E. MacLenathen, Arch. Internal Med. 60, 264 (1937). 



