American Journal of Clinical Nutrition, Vol 19, 398-406, Copyright © 1966 by The American Society for Clinical Nutrition, Inc.

Metabolic Patterns in Preadolescent Children

Thiamine Utilization in Relation to Nitrogen Intake

¹ From the School of Home Economics, University of Kentucky, Lexington, Kentucky

Thiamine intake, excretion and content in whole blood were determined for twenty-four normal preadolescent girls maintained on controlled diets, the experimental variable of which was protein. Mean thiamine intake for twelve girls in a fifty-six day experimental period was somewhat less and for twelve girls in a forty-eight day experimental period slightly more than the National Research Council recommended allowances. Intake was adequate as evaluated on the basis of mean daily urinary excretion of 20 per cent of intake and 180 µg. of thiamine per gm. of creatinine.

Both thiamine and nitrogen intakes were significantly related to urinary excretion of thiamine for the twelve girls whose daily mean intakes of thiamine were 20.6 to 29.1 µg. per kg. and of nitrogen 0.301 to 0.432 gm. per kg. body weight. For the twelve girls whose daily mean intakes of thiamine were 35.8 to 37.4 µg. per kg. and nitrogen 0.103 to 0.128 gm. per kg. body weight, the relationship was not significant.

Fecal thiamine values appeared to be independent of either thiamine or nitrogen intake.

In experiment 1 (fifty-six days) the thiamine content of whole blood was higher for eight subjects and lower for three subjects at the end compared to the beginning of the study, and for one subject it was the same. Influence of size, and possibly size as related to nitrogen intake, was shown by variance analysis. In experiment 2 (forty-eight days), in which nitrogen intake was low, eight subjects had lower and four subjects had somewhat higher blood values at the end compared to the beginning of the study. Although there was no strong evidence of interrelationship of nitrogen and thiamine metabolism, there were indications of nitrogen influence in both urinary and blood thiamine determinations.