Provision of water-soluble vitamin supplementation for haemodialysis patients

Abstract

Background: The 2010 Clinical Practice Guidelines for Nutrition in Chronic Kidney Disease (CKD) by the UK Renal Association (Wright et al., 2010) recommend that haemodialysis patients should be prescribed daily supplements of water soluble vitamins, to replace intra-dialytic losses. A specific vitamin tablet or range of vitamins is not specified within these guidelines. This study aimed to explore the adoption of these guidelines in renal units in the UK and the suitability of existing vitamin formulations. Methods: Renal Dietitians registered with the BDA Renal Nutrition Group (RNG) were contacted and asked to fill in a questionnaire. The questionnaire established whether the unit routinely prescribed vitamins for all haemodialysis patients, haemodialysis patients with an identified need or not at all. If not a blanket referral it asked for a justification for the decision. For units only recommending vitamins for patients with an identified need it asked what criteria needed to be met. All respondents were asked which vitamin they recommended for haemodialysis patients when required and in what dosage. The questionnaire also asked whether the funding for the prescription came from the renal unit budget, the GP, the PCT or another source. The individual micronutrient contents of vitamin preparations identified by the questionnaire were compared with the levels set out in the European Best Practice Guidelines (Fouque et al., 2007) using an excel spreadsheet. Results: Questionnaires were returned from 24 different renal units, of which 14 (58%) provided water-soluble vitamins for ALL haemodialysis patients, six for selected patients only, and four didn't recommend any vitamins. Criteria for prescribing vitamins included: for those on dietary restrictions (e.g. low potassium), a consultant decision, for those on haemofiltration and for those with a poor nutritional intake. There were 12 different combinations of vitamins prescribed in varying doses, ranging from daily prescriptions to dialysis days only. The most commonly used vitamin preparation was Dialyvit®, used by 45% of centres. Reasons for not prescribing included: preferring to use food to meet requirements where able, reluctance to add another tablet to what is already a high number medications required by haemodialysis patients, insufficient evidence, financial constraints on the prescriber and no product meeting the need. Funding for the vitamin came from the GP in 68% of cases. Dialyvit® was the vitamin with the best nutrient profile, providing the closest levels of eight of the nine water-soluble vitamins when compared to levels in the European Best Practice Guidelines. Discussion: Results show that the provision of water-soluble vitamins for haemodialysis patients varies across the UK, with only 58% of the units responding providing routine replacement. It is difficult to meet the increased requirements for water-soluble vitamins through food alone when the majority of these patients are on low potassium diets which require limiting certain fruit and vegetables. Despite a lack of robust evidence guidance acknowledges vitamin provision as a low cost, low risk practice which may reduce morbidity and mortality. To our knowledge, the European guidelines are the only ones who include guidance on individual nutrients and their specific requirements. From the range of vitamins used in the UK Dialyvit® meets these recommendations most closely and is only one tablet daily, compared with other preparations which would increase the pill burden. Conclusion: Current UK practice for prescription of water-soluble vitamins to haemodialysis patients is variable despite recent guidelines and the availability of a supplement which meets the need.