Vitamin B6 deficiency was common among Israeli hemodialysis patients treated with high-flux dialyzers despite a presumed Mediterranean diet, and was not associated with nutritional status, suggesting dialysis-related losses may outweigh intake.
Key Findings
Results
Vitamin B6 deficiency was found in 63% of unsupplemented hemodialysis patients treated with high-flux dialyzers.
Deficiency was defined as plasma pyridoxal-5'-phosphate (PLP) < 20 ng/ml.
Median PLP level was 18 ng/ml with an interquartile range of 13–23 ng/ml.
The study included 27 chronic hemodialysis patients not receiving vitamin B6 supplementation.
All patients were treated with high-flux (HF) dialyzers.
The cohort represented the available unsupplemented patients from a unit of approximately 150 patients.
Results
No significant correlations were found between PLP levels and nutritional indices or laboratory markers.
Clinical and nutritional parameters were evaluated to identify predictors of deficiency.
The absence of association with nutritional status suggests dialysis-related losses, rather than dietary intake, may be the primary driver of deficiency.
The study population was presumed to follow a Mediterranean dietary pattern, which is generally considered nutritionally adequate.
This finding distinguishes dialysis-related loss as a likely predominant mechanism over dietary insufficiency.
Results
A non-significant trend was observed between older age and lower PLP levels.
The correlation coefficient between age and PLP levels was r = -0.35, P = 0.098.
The median age of the cohort was 74 years.
The cohort was 67% male.
The trend did not reach statistical significance, possibly due to the small sample size of 27 patients.
The authors noted that routine supplementation may be particularly warranted in older patients.
Discussion
High-flux dialysis membranes may augment vitamin B6 losses during dialysis, contributing to deficiency despite dietary intake.
All patients in the study were treated with high-flux (HF) dialyzers.
The authors noted that data related to high-flux dialysis membranes and Mediterranean dietary patterns were scarce prior to this study.
High-flux membranes are capable of clearing larger molecules and may increase losses of water-soluble vitamins such as B6.
The authors suggest dialysis-related losses 'potentially augmented by high-flux membranes, may outweigh intake.'
Conclusions
The authors concluded that routine low-dose vitamin B6 supplementation may be warranted for hemodialysis patients, particularly older ones.
The recommendation was based on the high prevalence of deficiency (63%) and the low cost of supplementation.
Vitamin B6 deficiency is linked to neuropathy, anemia, and cardiovascular risk.
The study design was a retrospective chart review with a cross-sectional design conducted in August 2024.
The small sample size of 27 patients was noted as a limitation, as it represented only the unsupplemented cohort from the unit.
What This Means
This research examined how common vitamin B6 deficiency is among kidney patients receiving hemodialysis (a blood-filtering treatment) who were not taking vitamin B6 supplements. The study looked at 27 patients in Israel, all treated with modern 'high-flux' dialysis filters. Researchers found that nearly two-thirds of these patients (63%) had vitamin B6 levels below the threshold considered adequate, with a median blood level of 18 ng/ml against a cutoff of 20 ng/ml. Notably, deficiency was not linked to how well-nourished patients were, suggesting that the dialysis process itself — rather than poor diet — is the main cause of vitamin depletion.
This finding is significant because Israel has a Mediterranean dietary pattern, which is generally considered a healthy and nutritionally rich diet. Despite this presumed dietary advantage, deficiency remained highly prevalent, pointing to dialysis-related losses as the key factor. Modern high-flux dialysis membranes, which are more efficient at filtering the blood, may also remove more water-soluble vitamins like B6. The study also found a trend — though not statistically significant — suggesting older patients may be at even greater risk of deficiency.
This research suggests that hemodialysis patients, especially older ones, may benefit from routine low-dose vitamin B6 supplementation regardless of their diet, given how common deficiency appears to be and how inexpensive supplementation is. Vitamin B6 is important for nerve function, red blood cell production, and heart health, making its deficiency a clinically meaningful concern for this vulnerable population. The authors call for larger studies to confirm these findings and refine supplementation recommendations.
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Rabina E, Baharal Bergner T, Nacasch N, Levian A, Rashid G, Neumark E, et al.. (2026). Prevalence and Predictors of Vitamin B6 Deficiency in Hemodialysis Patients Not Receiving Vitamin Supplementation.. The Israel Medical Association journal : IMAJ. https://pubmed.ncbi.nlm.nih.gov/42701843/