Measurement of Vitamin K Metabolites in Neonatal Faecal Matter by HPLC with Electrochemical Detection

Background: Vitamin K deficiency of the newborn is preventable by routine administration of vitamin K1 post-partum. Although this practice is essentially successful, little is known about the efficacy of the dosage, the preferred route of administration and variations required for safe treatment of term and preterm neonates. Methods: We describe a method which has been successfully employed for the determination of the 5C- and 7C-metabolites of vitamin K in neonatal faecal matter by HPLC with redox-mode electrochemical detection. Results: Peaks attributable to the 5C- and 7C-metabolites of vitamin K were detected in neonatal faecal material post prophylaxis. Metabolite identity was confirmed by chromatographic retention time compared to pure standards and by LCMS. Vitamin K metabolite elimination curves were in line with that expected post vitamin K1 administration. Conclusion: The method described is suitable for investigation of vitamin K metabolism post vitamin K prophylaxis in term and preterm neonates.