Elevated pre-sepsis vitamin B12 levels associated with increased 90-day mortality in adults with sepsis.

BackgroundElevated serum vitamin B12 levels have been associated with adverse outcomes in various clinical settings; however, the prognostic significance of pre-existing vitamin B12 elevation measured before sepsis onset remains unclear. This study examined the association between pre-sepsis vitamin B12 levels and clinical outcomes in adults with sepsis.MethodsThis retrospective cohort study utilized the TriNetX database to identify adults diagnosed with sepsis between 2010 and 2024. Patients with elevated vitamin B12 levels (≥1,000 pg./mL) measured within 3 months before sepsis diagnosis were compared with those having normal levels (300–900 pg./mL) using 1:1 propensity score matching. The primary outcome was 90-day all-cause mortality. The secondary outcomes included major adverse cardiovascular events, organ failure, intensive care unit (ICU) admission, and progression to severe sepsis.ResultsAfter propensity score matching, 18,830 patients per group (37,660 patients in total) were included in this cohort. Elevated pre-sepsis vitamin B12 levels were associated with increased 90-day mortality [26.3% vs. 21.8%; hazard ratio (HR): 1.29, 95% confidence interval (CI): 1.24–1.35, p