A study of the amount of ascorbic acid (vitamin C) necessary to maintain tissue saturation in college girls
A saturation study was conducted on three normal college girls, weighing 50, 43, and 54 kg. Subject I was found to require more than 2.2 mg. per kg. of ascorbic acid or a total of 110 mg. To maintain tissue saturation and subjects II and III were found to require 1.6 mg. per kg. or a total of 67 mg. And 86 mg. respectively.
The data for subjects II and III suggest that they may be a relationship between body size and the ascorbic acid requirement, since on the per kg. basis, they both needed the same (1.6 mg. per kg.). However, the fact that subject I required a much greater amount to maintain tissue saturation, more than 2. mg. per kg. Indicates that individual difference may overshadow body size in its effect on requirement of vitamin C.
The effect of various factors on the ascorbic acid excretion were observed:
a. The correlations between the percentage of ascorbic acid intake excreted and the urinary pH were -.2122, -.315, and -/8588 for subjects I, II, and III respectively, only that of subject III being significant.
b. Insignificant correlations of .293, -.2015, and -.0507 were found between the urinary volume and the percentage of ascorbic acid excreted.
c. Correlations for subjects I and II between ascorbic acid excretion and cigarettes smoked were .0243 and .3198. Neither was considered significant.
d. Insignificant correlations, -.149 and .00286, were found between ascorbic acid excretion and the coffee intake.
e. A slightly significant correlation of -.3848 was found between the percentage (Average for the three subjects) of the ascorbic acid intake excreted and the maximum daily temperature.
A comparison of the results of this saturation study with two other saturation studies (2, 24) points out that 1.6-1.7 mg. per kg. May be an adequate requirement in most of the cases studied. However, all three studies give data on only thirteen subjects.
Suggestions are offered which it is hoped will so simplify the procedure of the saturation test that with efficient planning a much larger number of subjects may be studied:
a. Collection and analysis of urine only on test dose days.
b. Ad libitum intake of foods containing negligible amounts of vitamin C.
c. Determination of the urinary pH at the time of collection.