Riboflavin excretion in normal and diabetic rats.

Twenty-four hour urinary excretion of riboflavin was determined in normal and short-term and long-term streptozotocin diabetic rats. Compared to non-diabetic rats (controls), short-term (1 week) diabetic rats had no increased urinary riboflavin. In contrast, long-term (20 week) diabetic rats excreted significantly elevated levels of urinary riboflavin. Results suggest that the reported riboflavin deficiency seen in chronic diabetes may be related to augmented urinary excretion of riboflavin.