Is vitamin B6 supplementation appropriate for patients with end-stage renal disease undergoing dialysis?

Vitamin B6 Supplementation in Dialysis Patients

Yes, vitamin B6 supplementation is appropriate and recommended for dialysis patients, with a daily dose of 10 mg pyridoxine-HCl for adult hemodialysis and peritoneal dialysis patients to correct documented deficiency. 1

Why B6 Supplementation is Necessary

Dialysis patients are at high risk for vitamin B6 deficiency through multiple mechanisms:

• Dialytic losses: Hemodialysis and peritoneal dialysis actively remove vitamin B6 from the blood, with dialysis reducing plasma levels by 28-48% depending on the dialyser used 2
• Low dietary intake: Multiple surveys document that 67% of children and 26 of 30 pediatric dialysis patients consume less than the RDA, with similar findings in adults 1
• Documented biochemical deficiency: Low blood levels (measured as plasma pyridoxal-5-phosphate) are consistently found in both hemodialysis and peritoneal dialysis patients, with deficiency rates ranging from 24-56% in recent studies 1, 2
• Medication interactions: Various medications commonly used in dialysis patients interfere with pyridoxine and folate metabolism 1

Recommended Dosing

For adult hemodialysis patients:

• 10 mg/day of pyridoxine-HCl is the established dose that has been proven to correct vitamin B6 deficiency 1, 3
• This is the lowest dose demonstrated to rapidly correct abnormal vitamin B6 status and maintain normal values 3
• During sepsis or when taking vitamin B6 antagonists, 10 mg/day remains the safer supplement 3

For peritoneal dialysis patients:

• Most patients respond adequately to 5-10 mg/day of pyridoxine-HCl 4
• Eight of eleven patients achieved normal levels with 5 mg/day, while three required 10 mg/day 4
• Peritoneal losses are relatively small (8 nmol PLP/day) compared to hemodialysis 4

For pediatric patients:

• Lower supplemental doses in addition to dietary intake are likely sufficient based on marked increases in blood levels with 10 mg supplements in this population 1

Current Guideline Consensus

The most recent 2024 ESPEN guidelines identify vitamin B6 as one of the most deficient micronutrients in chronic hemodialysis patients (35.1% deficiency rate) and recommend that water-soluble vitamin losses during kidney replacement therapy should be monitored and replaced 1

The 2009 KDOQI guidelines specifically state that a daily pyridoxine-HCl supplement of 10 mg has been recommended for adult hemodialysis and peritoneal dialysis patients because this is the lowest dose that has been proved to correct pyridoxine deficiency 1

Monitoring Considerations

• Plasma pyridoxal-5-phosphate is the preferred measure of vitamin B6 status, assessed via HPLC 1
• Blood levels should be monitored periodically, especially in patients with signs of deficiency 5
• The erythrocyte glutamic pyruvic transaminase (EGPT) index can also assess vitamin B6 adequacy 3

Important Caveats

• Patients with good dietary intake or those receiving specialized renal formulas may already meet vitamin requirements and should be assessed individually 5
• While vitamin B6 supplementation corrects biochemical deficiency, high-dose B vitamin combinations (B6, B9, B12) studied for cardiovascular outcomes in dialysis patients have not shown reductions in patient-important outcomes in adequately powered trials 6
• The primary goal is to prevent deficiency and maintain normal vitamin B6 status, not to achieve supraphysiologic levels 1