Water‐Soluble Vitamin Levels in Patients Undergoing High‐Flux Hemodialysis and Receiving Long‐Term Oral Postdialysis Vitamin Supplementation

Abstract

The prescription of multivitamin supplements for dialysis patients is routine practice, but the doses prescribed differ greatly from one dialysis center to another. Few data are available concerning long-term vitamin supplementation and its effects on patients either on high-flux hemodialysis or receiving postdialysis supplementation. For several years, we have systematically prescribed to our patients an oral postdialysis multivitamin supplement containing thiamine hydrochloride 100 mg, riboflavin 20 mg, pyridoxine hydrochloride 50 mg, folic acid 6 mg, and ascorbic acid 500 mg. The aim of this study was to perform a cross-sectional long-term evaluation of the vitamin levels in patients who received this vitamin supplement for at least 12 months. We also were interested in investigating the plasma oxalic acid and total homocysteine levels associated with the long-term prescription of these vitamin supplements. Thirty-three patients on high-flux dialysis were studied. Vitamin levels and/or vitamin-dependent enzymatic activities were within the normal range (N) in all patients. The mean results (+/-SD) were plasma ascorbic acid 13.6 +/- 6.4 mg/L (N > 4), plasma folate 14.1 +/- 1.1 microg/L (N > 3), for vitamin B1, alpha-ETK 1.02 +/- 0.02 (N < 1.18) and ETKo 100 +/- 13 U/L (N > 70), for vitamin B2, alpha-EGR 1.00 +/- 0.07 (N < 1.52) and EGRo 1282 +/- 213 U/L (N > 672), and for vitamin B6, alpha-EGOT 1.34 +/- 0.10 (N < 1.8) and EGOTo 380 +/- 84 U/L (N > 228). Plasma oxalic acid was higher than normal in all patients (mean = 61 +/- 15 micromol/L, N < 33). However, all patients had oxalic acid levels within the range reported in the literature for patients not taking extra ascorbic acid. Mean total homocysteine was 24 +/- 8 micromol/L with only 4 patients (12%) having normal levels (N < 15). In conclusion, the postdialysis supplement given provides adequate vitamin levels in almost all patients in the long term. Postdialysis prescription allows an optimal compliance with the treatment, is well accepted by the patients, and is cost-effective.

Thiamine Diphosphate Status and Dialysis-Related Losses in End-Stage Kidney Disease Patients Treated with Hemodialysis

“…Consistent to the findings of previous reports, we have not identified significant thiamine deficiency in pre-dialysis measurements as compared to reference values for healthy humans [14,15,17,20,21]. However, in view of high concentrations of oxythiamine, an antythiamine compound, reported recently in ESRD by Zhang et al [5], the reference concentrations of thiamine might not necessarily comply with its increased needs in hemodialysed patients.…”

Association Between Adherence to Folic Acid Supplements and Serum Folate, and Plasma Homocysteine Among Hemodialysis Patients

“…Non-adherence to such vitamin supplement prescriptions is common among hemodialysis patients and may influence their health and outcomes 26–28, 37–38. We found, as have others, that by providing patients with a free supplement, we removed a potential financial barrier, improved physical access to supplements, and encouraged their use and supplement adherence 19, 28. Improved adherence had an effect on total folic acid intake, serum folates and plasma homocysteines.…”

“…Only a few studies have reported adherence to vitamin supplement prescriptions among hemodialysis patients 19, 28. Psychosocial, physical and economic constraints may all cause inadequate intakes of both supplements and foods 29–30.…”

“…These barriers include lack of understanding in the importance of supplement use, lack of motivation, poor self care patterns, inability to remember medication schedules, and lack of financial resources (supplement purchases are not covered by the Medicare End Stage Renal Disease Program and the supplements may be unaffordable) 29–30. Removing financial barriers to supplement use by providing them free of charge to patients or educating and motivating patients on why they should use supplements appear to increase adherence 19, 28.…”

Current Studies on Oxidant Stress in Dialysis

“…Our data also indicate that peritoneal dialysis patients enjoy more satisfactory vitamin C status. These findings suggest that several factors need to be addressed [40]: Are vitamin C supplements readily available to all hemodialysis patients? Are they compliant with the vitamin prescription?…”