Prevalence and Predictors of Vitamin B6 Deficiency in Hemodialysis Patients Not Receiving Vitamin Supplementation.

BACKGROUND

Vitamin B6 is an essential cofactor in amino acid metabolism. Its deficiency is linked to neuropathy, anemia, and cardiovascular risk. Deficiency is common among hemodialysis patients due to dialytic losses and restrictive diets; however, data related to high-flux (HF) dialysis membranes and Mediterranean dietary patterns are scarce.

OBJECTIVES

To assess the prevalence and determinants of deficiency in unsupplemented Israeli hemodialysis patients.

METHODS

This retrospective chart review, utilizing a cross-sectional design, was conducted in August 2024. We included 27 chronic hemodialysis patients not receiving vitamin B6 supplementation, representing the available unsupplemented cohort from a unit of approximately 150 patients. Vitamin B6 status was assessed by measuring plasma pyridoxal-5'-phosphate (PLP); deficiency < 20 ng/ml. Clinical and nutritional parameters were evaluated to identify deficiency.

RESULTS

Vitamin B6 deficiency was noted in 63% of patients (median PLP 18 ng/ml, interquartile range 13-23). The cohort was 67% male, median age 74 years. All patients were treated with HF dialyzers. No significant correlations were found between PLP levels and nutritional indices or laboratory markers. A non-significant trend was observed between older age and lower PLP levels (r = -0.35, P = 0.098).

CONCLUSIONS

Vitamin B6 deficiency was common among Israeli hemodialysis patients treated with HF dialyzers, despite a presumed Mediterranean diet. It was not associated with nutritional status, suggesting dialysis-related losses, potentially augmented by high-flux membranes, may outweigh intake. Given the high prevalence of deficiency and low cost, routine low-dose vitamin B6 supplementation may be warranted, particularly in older patients.