Experiments on Nutrition. VI

Abstract
Experiments on chicks, ducks, pigeons and rats indicate that protein, fat and carbohydrate in the diet need balancing by vitamin B (B1+B2), and that the supply of vitamin B must be proportionate to the caloric value of the diet. In the case of chickens, the quantity of dried yeast which carries the required vitamin B can be represented by dried yeast/calories = 1/40 to 1/60 or from 6 to 10% in a diet containing no vitamin B. For adult pigeons, the ratio is about 1/80 or 4% of the diet; for adult rats, the ratio is 1/160, or 2% of the food. When tested on pigeons, 8% of marmite corresponded to 4% of dried yeast. Samples of yeast extract have been found to vary considerably in their vitamin B content. Young animals require more vitamin B than adult animals. The authors suggest, therefore, that vitamin B is a constituent of the nucleus of the cell, and is required for growth and for the replacement of wear and tear.