B6 and Bleeding: A Case Report of a Novel Vitamin Toxicity.

Pyridox(am)ine-5-phosphate oxidase deficiency is an inborn error of vitamin B6 metabolism that is characterized by neonatal seizures, requiring lifelong therapy with pyridoxal-5-phosphate. We present the first case of a patient with pyridox(am)ine-5-phosphate oxidase deficiency and mild hemophilia A, whose bleeding symptoms were exacerbated by the vitamin B6 therapy essential for his epileptic disorder. This report expands the spectrum of known vitamin B6 toxicity and demonstrates a need for vigilance in monitoring for bleeding symptoms in patients requiring pyridoxine or pyridoxal-5-phosphate supplementation.