Water Soluble Vitamins and Trace Elements Loss in Hemodiafiltration Patients

We would like to measure water-soluble vitamins (B1, B6, B9, B12, C) and trace elements (zinc, selenium) in blood and dialysate for the patients treated by online post-dilution hemodiafiltration patients. There measures on blood are done systematically during the half-yearly report of our patients in our hemodialysis center. Only results are collect for the study.