The study reported in this thesis is part of an investigation designed to determine the metabolism of thiamine and riboflavin in human subjects who were maintained on controlled diets. Part of this investigation was made during a 30-day experimental period in 1950 and the other part, during a 30-day experimental period in 1951. In the studies of both years, the subjects were maintained on a diet which was adequate in all nutrients except thiamine and riboflavin. With respect to thiamine, each of the 30-day studies was divided into two experimental periods of 15 days each. During the first 15-day period, the National Research Council's recommended allowance of 500 mcg. thiamine per 1000 calories per person per day was tested and in the second period, each subject received 300 mcg. thiamine per 1000 calories daily in the diet. The daily intake (about 1.2 mg.) of riboflavin was constant throughout the whole study.
This thesis is a report of the riboflavin phase of the study only.
Four women were selected as subjects for each year's 30-day experiment. In general, they were healthy throughout the entire period of the study.
Daily micro determinations of the concentration of free (+FMN) and total riboflavin in the serum and daily macro determinations of riboflavin excreted in 24-hour collections of urine were made.
Based on the results of the studies of both years, the mean concentration of free (+FMN) serum riboflavin for seven subjects (data for one subject were omitted) was 1.43 and ranged between 0.47 to 3.5 mcg. percent regardless of the different levels of thiamine intake; the mean concentration of total serum riboflavin was 3.22 and ranged from 2.36 to 5.30 mcg. percent.
The mean concentration of free (+FMN) riboflavin in the serum was slightly, but not significantly lower on the period of restricted thiamine intake. The mean concentration of total riboflavin increased 0.43 mcg. percent in the period of restricted thiamine intake; this increase was statistically significant. This phenomenon may have been due to the effect of thiamine on the utilization of riboflavin in metabolism; i.e., a decrease in thiamine intake reduces the requirement for riboflavin and is reflected in an increased concentration of riboflavin in the serum.
The statistical analysis indicated that the variation among individuals in serum riboflavin concentration is statistically significant. There was no significant day-to-day variation in the riboflavin value in serum during the period of study.
The mean daily urinary excretion of riboflavin of three subjects (data for one subject were omitted) in the 1950 study was 382 mcg. per day, and that of four subjects in the 1951 study, 376 mcg. per day. The riboflavin output was about 32 percent of the ingested vitamin in both years' studies. The riboflavin excretion per gram of creatinine ranged from 248 to 474 mcg. / Graduation date: 1951
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26318 |
| Date | 14 May 1951 |
| Creators | Wu, Mei-Ling |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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