A Test Proposed to Measure Vitamin B 1 Saturation in Humans

Abstract

A test designed to measure the individual patient's saturation with respect to Vitamin Bi would have a wide clinical application. Experiments have been carried out in an attempt to develop such a procedure. The validity of such a test depends upon, among other things, the accuracy of the method of assay for the Vitamin B₁. The assay methods fall into two categories—chemical and biological. The chemical methods on the whole are specifically for pure thiamin. Among the biological methods the Schultz, Atkins and Fry technic which employs the rate of fermentation of glucose by a yeast is the most suitable for clinical investigation. This method measures not only the thiamin but the pyrimidines as well. The pyrimidines present in the urine may be considered for practical purposes as originating from the members of the B complex. The actual test in its present form employed in this laboratory is summarized as follows:

Patients were injected with 1 mg of thiamin hydrochloride intramuscularly in the fasting state. The urine was collected for a 4-hour period following the injection. The Vitamin B₁ activity of this collected urine was assayed by means of the Schultz, Atkins and Fry yeast fermentation method. Fig. 1 shows the tabulation of the results of the test on 349 unselected patients. The distribution curve of the results indicates that an excretion of 180 gammas or more in the 4-hour period represents the average normal. Patients excreting less than 180 gammas may be considered as below average saturation. This group of patients represents the population of hospitals and dispensaries and cannot be considered a representative cross section of the population. Fig. 2 shows the tolerance test on 35 normal, healthy students, instructors and physicians.