Red cell transketolase as an indicator of nutritional deficiency.

Twenty patients who had symptoms that were apparently neurotically functional are reported because they proved to have abnormal red cell transketolase activity. Although in many of the cases the etiology appeared to be associated with heavy consumption of "junk" foods, carbonated or sweet beverages, and candy, this was not so in all of them and the etiology in these cases remains obscure. The symptoms in all 20 patients could be correlated with those well documented in early beriberi and all were clinically improved by the administration of thiamin. In only two cases were other vitamins administered. Such improvement was slow and there were no dramatic recoveries. In 10 patients improved transketolase activity was correlated with clinical well-being. The other 10 patients did not keep their return appointments. Telephone contract revealed that they were asymptomatic.