Routine Folic Acid and Vitamin B12 Supplementation in Hemodialysis Patients: A Cross‑Sectional Analysis of Achieved Serum Levels

Introduction: Patients undergoing maintenance hemodialysis are routinely supplemented with folic acid and vitamin B12 to prevent deficiency related to dietary restrictions and dialytic losses. However, contemporary data on achieved serum vitamin levels under routine supplementation practices are limited. Methods: We conducted a single-center observational study including adult patients undergoing maintenance high-flux hemodialysis or hemodiafiltration. All patients received standardized supplementation with folic acid and vitamin B complex three times per week. Serum folic acid and vitamin B12 concentrations were measured in January 2024, and associations with clinical, laboratory, and dialysis-related variables were explored. Results: A total of 53 patients were included (mean age 72.7 ± 11.5 years; 32.1% female). Serum folic acid levels were markedly elevated, with 94.3% of patients presenting values above the upper reference limit. Elevated serum cobalamin concentrations were observed in 28.3% of patients. A higher proportion of patients treated with high-flux hemodialysis presented vitamin B12 levels above the reference range compared with those undergoing hemodiafiltration, although no significant differences in mean serum vitamin levels were observed between dialysis modalities. Serum vitamin levels were not associated with dialysis adequacy or other clinical and laboratory parameters. Conclusion: Routine supplementation with folic acid and vitamin B12 in maintenance hemodialysis patients is associated with high achieved serum vitamin levels. The higher proportion of elevated vitamin B12 levels observed in high-flux hemodialysis patients warrants further investigation and supports the need to re-evaluate and potentially individualize supplementation strategies in contemporary hemodialysis care.