Vitamin B Testing Revised.

Abstract

The demonstration by Smith and Hendrick, 1 Goldberger and coworkers, 2 and others 3 in this country that what we have called vitamin B is composed of at least two factors, each with specific functions and properties, necessitates the revision of existing vitamin B tests. In England, Chick and Roscoe 4 have been able to confirm the contentions of Goldberger. They showed that wheat embryo is distinctly richer in antineuritic factor than in antipellagric factor, by utilizing autoclaved yeast as the source of antipellagric and a preparation of Peters to supply the antineuritic. The Peters' fraction was separated by Kinnersley and Peters 5 of Oxford University by controlling the selective adsorption of norite. During the past year Williams and Waterman of our laboratory have also succeeded in separating a yeast fraction which is antineuritic, but is apparently free of the factor (antipellagric) which is present in autoclaved yeast. Their separation was attained by controlling the selective adsorption of fuller's earth. 6

In contrast to the alcoholic extract of corn meal used by Gold-berger, Williams' preparation has supplied a testing fraction entirely devoid of antipellagric factor. To date we have been able to use this preparation in retesting two sources of vitamin B.

Last year we reported that ripe banana tested by the Sherman method must be supplied to rats on B-free, but otherwise adequate diet, in quantities of 8 to 10 gm. daily, to permit a growth gain of 20 gm. in 60 days. Using 5 mg. daily of the Williams' preparation as adequate source of antineuritic, we find that 2 gm. of banana daily supplies enough antipellagric factor to produce 20 gm. gain in 60 days, and that 6 gm. daily is nearly adequate for normal growth. By using autoclaved yeast as antipellagric, we find that at least 6 gm. of banana daily must be added to prevent growth decline.