Further Observations on Riboflavin as a Food Factor in Economy of Food Utilization

Abstract

This study was carried out with ten pairs of male rats by the paired feeding method of experimentation on two types of diets. The average gain in body weight of the riboflavin deficient animals, during an average experimental period of 125 days, was 6.1 gm. per rat, while during the same period of time on the same amounts of the same ration the litter mate controls, by virtue of having received 20 μg. riboflavin daily, gained 61.3 gm. per animal. To demonstrate the greatest influence that riboflavin exerts in economy of food utilization, experiments should be started on animals weighing 55 to 70 gm. rather than 30 to 45 gm. Experimental evidence has been submitted showing that, unlike in thiamine deficiency which is accompanied with a progressive inanition ultimately approaching starvation, in riboflavin deficiency there is no complicating marked anorexia in the terminal stages of the disease. There may be a moderate reduction, no reduction, or even an increased food intake in the last stages of riboflavin avitaminosis. The riboflavin deficient rats show alopecia, dermatitis at the denuded areas of the skin, rough hair, conjunctivitis, keratitis, and premature senility. Since riboflavin is concerned with oxidative-enzymic processes essential for normal metabolism, it is suggested that a deficiency of this vitamin may produce a waste of products of metabolism which ultimately results in collapse of the animal organism.