HDCN Article Review/Hyperlink

Kasama R, Koch T, Canals-Navas C, Pitone JM

Vitamin B6 and hemodialysis: the impact of high-flux/high- efficiency dialysis and review of the literature

Am J Kidney Dis (May) 27:680-686 1996

It is well accepted that patients on chronic dialysis need supplementation with water-soluble vitamins, including the B-complex vitamins. Serum levels of vitamins are dependent not only on their intake and absorption but also on their clearance from the dialyzer. However, there is very little information available regarding the clearance of vitamins by high-flux dialyzers. Kasama et al. and his group studied in vivo clearances of serum pyridoxal-5' phosphate (PLP), the active metabolite of vitamin B-6, in patients receiving 10 mg per day of pyridoxine supplements for patients receiving standard cuprophan dialyzers versus cellulose triacetate high-flux, high-efficiency dialyzers. In this crossover study, patients received the same dose of dialysis in both the standard dialysis arm and the high-flux, high-efficiency arm (average Kt/V of 1.45), and their average protein catabolic rates were also similar (0.95-1.0 g/kg/body weight/day) in both study arms. However, pre-dialysis vitamin B-6 levels decreased from 53 ng/mL in patients on standard dialysis to 24 ng/mL after receiving 3 months of high-flux, high-efficiency dialysis. In addition, a marked increase in PLP clearance was noted from 86 mls/minute on standard dialysis up to 173 mls/minute on high-flux, high-efficiency dialysis. In 4 of the 6 patients who then crossed back to standard dialysis, their serum levels again increased back into the normal range after receiving standard dialysis for at least 3 months

Comment: This study is the first study to rigorously assess the impact of high-flux dialysis on serum vitamin levels. Undoubtedly, other water-soluble vitamins are also cleared more efficiently on high-flux dialysis than on standard dialysis. Additional research will be needed to determine the appropriate supplementation of water-soluble vitamins in patients who are receiving high-flux hemodialysis. Michael V. Rocco, M.D., Bowman Gray School of Medicine