Abstract
To obtain the data for the reference intervals of blood thiamin and riboflavin, the blood thiamin and riboflavin levels in female were determined from healthy female students aged 21〜22 years with these two vitamin intakes above their Recommended Dietary Allowances(RDAs), which were calculated from mean intakes obtained from dietary records just before three consecutive days and one day time study. Blood thiamin and riboflavin levels were determined by precolumn thiochrome HPLC and lumiflavin reverse HPLC, respectively. Mean thiamin intake was 0.91±0.26 mg/day (n=192), and 78.6% of the subjects were found their thiamin intakes above the RDAs. Their meani ±2 standard deviation(SD) of the normalized distribution of blood thiamin level, as the reference interval, obtained from the subjects with intake above the RDA, was 35〜76 (54.6±10.1) ng/ml. Mean riboflavin intake was 1.20±0.31 mg/day (n=189), and 72.0% of the subjects showed their intakes above the RDA. Their reference interval of blood riboflavin level, obtained from the subjects with riboflavin intake above the RDA, was 58〜110 (84.7±11.6) ng/ml. No significant correlation was found between their blood levels and dietary intakes of these vitamins. The lowest limits of normalized vitamin intake in the subjects whose blood vitamin levels were within their reference .intervals, were no significant difference from the 5th RDAs for Japanese, if 20% safety margin for personal difference both and cookingloss (30% on thiamin or 25% on riboflavin) were added.
