Raimann JG, Abbas SR, Liu L, Larive B, Beck G, Kotanko P, Levin NW, Handelman G. The effect of increased frequency of hemodialysis on vitamin C concentrations: an ancillary study of the randomized Frequent Hemodialysis Network (FHN) daily trial. BMC Nephrol. 2019 05 17; 20(1):179.