Abstract
Studies were made, using mice, on the change of riboflavin metabolism due to the administration of antibiotics and on the mechanism of appearance of riboflavin deficiency caused by antibiotics. When the animals were fed on a sufficient diet, the growth was rather stimulated by the administration of antibiotics. Antibiotics did not affect on the delayed growth and the change of the bodily appearance caused by riboflavin deficiency or liver damage. By the administration of antibiotics, the amount of riboflavin and its ester ratio of each organ decreased, especially in the case of riboflavin deficiency or liver damage. Riboflavin deficiency caused by antibiotics might not only be due to the decrease of riboflavin content, but to the disturbance of riboflavin utilization, shch as that of phosphorylation, especially in liver damage. However, the real causes for riboflavin deficiency might be much complicated.
