Vitamin Requirements of Nursing Young

Abstract

A quantitative biological method has been perfected for the vitamin B requirements of nursing young which is sensitive to the extent of one milligram per nursling per day. A vitamin B unit, applied to nursing young, has been defined as follows: The vitamin B unit is the daily amount of vitamin B which must become available to a nursing young of the albino rat weighting 30 grams, in order to permit a gain of 10 grams in 7 to 10 days. One gram of a dehydrated baker's yeast, Federal brand, has been found to contain 7 units of vitamin B. Applying our quantitative biological method of assay to vitamin B concentrates we found variations to the extent that one gram contained as little as 14.4 units and as much as 125 units.