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The ascorbic acid requirements of older adolescents

The concentration of ascorbic acid in the plasma was determined on
four levels of ascorbic acid intake for seven day periods in 1946-47 and
on three levels of ascorbic acid intake for ten day periods in 1947-48.
The subjects, eight girls and eight boys, were 16 to 19 year old freshman
students at Oregon State College. All of the food eaten by the subjects
during the experimental periods was weighed and the quantities were
recorded. The reduced ascorbic acid in the foods was determined after
each meal by the method of Loeffler and Ponting (1942) and daily fasting
plasma ascorbic acid values were determined by the micro-method of Farmer
and Abt (1936). The data in this study were analyzed statistically by
testing the significance of the differences between the means and by
analysis of variance.
The recommended allowance of the National Research Council (1945)
for these subjects (80 mg for the girls and 100 mg for the boys) did not
maintain mean plasma values as high as their respective means during the
saturation period when they were receiving 200 mg of crystalline ascorbic
acid in addition to the ascorbic acid from their food. On the recommended
allowance all the mean plasma values for the girls were above 0.80 mg per
cent, ranging from 0.83 to 1.07. The boys values ranged from 0.67 to
0.91 mg per cent; two out of seven values were below 0.80 mg per cent
(data for one boy were excluded due to illness). A decrease in ascorbic
acid intake to 10 mg less than the recommended allowance of the National
Research Council made a statistically significant decrease in the plasma
ascorbic acid concentration for only two of the eight girls and for one
of the seven boys.
The plasma ascorbic acid concentrations of these subjects showed
individual variation even when the ascorbic acid intake was considered
on the basis of mg of ascorbic acid per kg of body weight.
The ten day experimental periods were more desirable than the periods
of one week. This was particularly true for the saturation period when
some of the subjects had been on diets low in ascorbic acid prior to the
study. / Graduation date: 1949

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27090
Date06 1900
CreatorsDavey, Bessie Louise
ContributorsStorvick, Clara A.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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