Production of Microcytic Hypochromic Anemia in Puppies on Synthetic Diet Deficient in Rat Antidermatitis Factor (Vitamin B6)

1Puppies showed normal rate of growth on purified casein diets, supplemented with concentrated vitamin B or thiamine, crystalline riboflavin, liver extract containing the chick antidermatitis (filtrate) factor and nicotinic acid but free from both riboflavin and the rat antidermatitis factor, and rice polish extract containing the rat antidermatitis factor (vitamin B6) free of the chick antidermatitis factor and riboflavin.2Severe microcytic hypochromic anemia developed in the puppies when rat antidermatitis (vitamin B6) factor was apparently the only missing component of the diet. This anemia was cured by addition to the diet of this missing factor.3Blacktongue was produced in the puppies whenever the liver extract containing nicotinic acid and chick antidermatitis (filtrate) factor was absent from the diet.