Deficient vitamin B12 levels are associated with increased delirium incidence in critically ill patients

In intensive care unit (ICU) patients, deficiency of vitamin B12 (cobalamin) occur often and may be associated with significant neurologic syndromes. Therefore, this study aimed to investigate the association between cobalamin (cbl) serum levels and the incidence of delirium in ICU patients.

In this multi-center, cross-sectional clinical study, adult patients with GCS (Glasgow Coma Scale) ≥ 8 and RASS (The Richmond Agitation-Sedation Scale) ≥ -3, without a history of mood disorders before ICU admission, were eligible for inclusion. After informed consent was obtained, clinical and biochemical characteristics of eligible patients were recorded on the first day and then daily during follow-up for seven days or until delirium was developed. The CAM-ICU tool was used to evaluate delirium. Moreover, the cbl level was measured at the end of the study to assess its association with the incidence of delirium.

Among 560 patients screened for eligibility, 152 could be analyzed. Logistic regression results indicated a high cbl level (>900 pg/ml) was independently associated with lower delirium incidence (P < 0.001). Further analysis revealed that the delirium rate was significantly higher in patients with deficient and sufficient cbl compared to the high cbl group (P = 0.002 and 0.017, respectively). In addition, surgical and medical patients and pre-deliric scores were negatively associated with high cbl (P = 0.006, 0.003, and 0.031, respectively).

We have shown that deficient and sufficient compared to the high cbl group were significantly associated with a higher delirium incidence in critically ill patients. Further controlled clinical studies are required to evaluate the safety and efficacy of high-dose cbl to prevent delirium in critically ill patients.