Appropriate Vitamin Therapy for Dialysis Patients

Dietary intakes and biochemical status of B vitamins in a group of children receiving dialysis

OBJECTIVE

We investigated the dietary intake and biochemical status of B vitamins (thiamin, riboflavin, vitamin B6, and vitamin B12) in a group of mainly unsupplemented children with endstage renal disease receiving dialysis, to determine if B vitamin supplementation is indicated.

DESIGN

This was a cross-sectional, observational clinical trial.

SETTING

Children with endstage renal disease were receiving dialysis, under the care of Renal Services, at Starship Children's Health (Grafton, Auckland, New Zealand).

PATIENTS

We studied 12 children (including 7 girls, and 8 children receiving peritoneal dialysis) mean age 7.8 +/- 5.3 years (SD).

INTERVENTION

Three-day diet records were collected and analyzed with FoodWorks software. Blood was collected for vitamin assay testing.

MAIN OUTCOME MEASURE

Dietary intake of B vitamins was measured as a percentage of recommended dietary intake (RDI) or adequate intakes (AIs) for age. Biochemical status was measured as the concentration of each B vitamin compared with reference ranges.

RESULTS

Mean intakes from diet alone comprised <100% of the RDI or AI for each B vitamin. Mean intakes, with nutritional support, reached >100% of the RDI or AI for each B vitamin. All children achieved >100% RDI or AI for thiamin, riboflavin, and vitamin B12. Two children who were not receiving nutritional support received <100% of the RDI for vitamin B6. Blood levels of B vitamins were normal to high, compared with reference ranges, for each B vitamin in all children, indicating adequate status.

CONCLUSIONS

Intakes were adequate in the majority of children. Status was adequate in all children. In this group of children undergoing dialysis, B-vitamin supplementation was not indicated.

Use of alternative medicine by patients with stage 5 chronic kidney disease

The use of complementary and alternative medicine (CAM) in the United States is growing at a remarkable speed. Herbal products and dietary supplements are CAM therapies that have grown faster than any other CAM treatments. Little information is available about herbs and dietary supplement use in the stage 5 chronic kidney disease population. These products contain a myriad of pharmacologically active compounds that, when used by people with kidney disease, may be hazardous. Members of the renal dietitian listserv were queried about herbs and dietary supplements reportedly used by dialysis patients. Up-to-date information on the use, safety, efficacy, adverse effects, and recommended dosages in the nondialysis population are presented for 24 products. In the dialysis population, Noni juice should be avoided because of its high potassium content. In addition, bulk-forming laxatives such as flaxseed should be used with caution because of the need for increased fluid intake. Dialysis practitioners should include specific questions about herbs and dietary supplement use in medical and nutrition histories, and they should increase their knowledge about these products to advise patients appropriately. A list of reliable sources of information for the health care provider on herbs and dietary supplements is also presented.

An evidence-based approach for dietitian prescription of multiple vitamins with minerals

Dietitians working in hospitals are routinely involved in assessing energy and macronutrient (ie, protein, fat, carbohydrate) requirements of patients. However, complete nutritional therapy requires a comprehensive review of vitamin and mineral requirements. Scientific evidence for vitamin and mineral supplementation is primarily based on healthy, free-living people. This raises clinical challenges for dietitians working with patients whose vitamin and mineral requirements are impacted by various diseases, conditions, and medical treatment. Dietitians are the best-positioned health professionals to lead an evidence-based approach toward recommending vitamin and mineral supplements. The dietitians at the Toronto Rehabilitation Institute were authorized through a medical directive to prescribe multiple vitamins with minerals and to discontinue orders for unnecessary vitamin supplements. This is an ongoing, advanced practice initiative that focuses on the clinical efficacy for and safety of supplementation with multiple vitamins with minerals. It involves assessing the strength of evidence as it emerges in the literature, determining its relevance to specific patient populations in the practice setting and re-evaluating clinical practices for potential applications. When dietitians assume advanced practice initiatives, they are better equipped to deliver high-quality patient care. Simultaneously, state-of-the-art dietetic practice heightens dietitian recognition as a valuable member of the health care team.

Hyperhomocysteinemia in hemodialysis patients: effects of 12-month supplementation with hydrosoluble vitamins

BACKGROUND

High-efficiency hemodialysis may induce a deficiency in hydrosoluble vitamins. Supplementation with B-complex vitamins has been shown to lower serum homocysteine concentrations in several groups, but relatively few studies have concerned hemodialysis patients. Our objectives were to determine the status in B-complex vitamins in a large cohort of unsupplemented hemodialysis patients and to assess the effects of supplementation with hydrosoluble vitamins on serum homocysteine over one year.

METHODS

Serum total homocysteine (tHcy), vitamin B12, folate, pyridoxal-5'-phosphate (P-5'-P; the active moiety of vitamin B6), as well as red blood cell folate concentrations, were measured in 168 chronic dialysis patients on three times weekly high-efficiency hemodialysis and not supplemented with hydrosoluble vitamins. Their methylenetetrahydrofolate reductase C677T (MTHFR) genotypes were also determined (homozygotes TT, heterozygotes CT, without mutation CC). All involved patients were then supplemented with hydrosoluble vitamins (once daily by mouth, DiaVite; R&D Laboratories, Minneapolis, MN, USA), and half of them were randomized to receive in addition 10 mg intravenously of folic acid posthemodialysis (30 mg intravenously per week). Serum tHcy was monitored after 6 and 12 months of supplementation in the 140 and 128 patients available for follow-up.

RESULTS

At baseline, serum and red blood cell folate concentrations were within normal limits in all patients except for two with borderline serum folate (mean values of 21 +/- 8 and 1195 +/- 454 nmol/L), whereas serum vitamin B12 and P-5'-P were below normal in 11 and 65 patients, respectively (mean values of 327 +/- 215 pmol/L and 19 +/- 16 nmol/L for the 168 patients). Initial tHcy levels were increased in all patients (mean 33.3 +/- 16.6 for a normal below 11.8 +/- 1.5 micromol/L); tHcy significantly decreased to 23.5 +/- 7.6 micromol/L after six months (P < 0.0001 vs. baseline) and to 21.7 +/- 6.1 micromol/L after 12 months (P < 0.0001 vs. baseline) for the entire group, but was normalized in only four patients at 12 months. After six months, the mean reduction in tHcy was slightly but significantly greater for patients receiving intravenous folic acid (12.2 +/- 18.5 micromol/L) compared with patients not receiving it (8.3 +/- 9.8 micromol/L, P < 0.05). However, at 12 months, no difference between both subgroups persisted. When considering the different genotypes, tHcy at baseline tended to be higher for TT than CT and CC (39.8 +/- 30.9 vs. 31.4 +/- 10.5 vs. 31.6 +/- 11.8 micromol/L) and decreased to respective values of 21.1 +/- 6.9 versus 21.4 +/- 6.1 versus 22.2 +/- 5.9 micromol/L at 12 months. The impact of the addition of folic acid to DiaVite appeared particularly significant in TT patients at six months.

CONCLUSIONS

(1) Hyperhomocysteinemia was present in 100% of our hemodialysis patients. (2) Nearly 40% of our unsupplemented hemodialysis patients were deficient in vitamin B6. (3) Supplementation with DiaVite(R) has resulted in significant tHcy reductions for all three genotypes. (4) The impact of the proposed supplementation protocol was found after six months and was maintained, but did not increase further after 12 months of the same regimen. (5) The addition of intravenous folic acid has been associated with a more pronounced decrease in tHcy in TT patients.