A DIRECT approach to the evaluation of nutritional status by quantitatively determining levels of specific nutritional factors in body tissues and fluids is receiving increasing attention. Darby1 has recently emphasized the desirability of obtaining laboratory studies to support the clinical evaluation, and Jolliffe, Tisdall, and Cannon2 have emphasized the need for specific information on blood levels of the vitamins of the B group. Therefore, we decided to accumulate data on thiamine by direct blood-level determination when an opportunity to study healthy children presented itself. We believe such data to be desirable to supplement information obtained from a variety of techniques, including clinical assessment of the patient, excretion studies of carbohydrate metabolites, and electrocardiographic determinations, all of which may reflect thiamine nutrition indirectly. A recent review of vitamin requirements in adolescence3 further emphasized the relative paucity of information on thiamine requirements during growth.
MATERIAL AND METHODS