To assess this relationship between Vitamin D and clinical measures and outcomes in Encephalitis patients. 

Encephalitis is inflammation of the brain, primarily divided into Autoimmune Encephalitis (AE) and Infectious Encephalitis (IE), and poses a substantial burden on the U.S. healthcare system with an inpatient mortality of ~10%. Previous studies suggest both infectious (SARS-CoV-2) and autoimmune (multiple sclerosis) conditions are associated with Vitamin D, where Vitamin D may aid in SARS-CoV-2 prevention/immunomodulation, and hypovitaminosis D is associated with multiple sclerosis development. Despite these findings, the relationship between Vitamin D and Autoimmune and Infectious Encephalitis remains unknown.

We conducted a retrospective cohort study using electronic health records from adult Encephalitis patients from 2013-2023 in Greater Houston and Baltimore areas. Vitamin D 1,25(OH)2 (ng/mL) and Vitamin D 25-OH (ng/mL) values at admission were dichotomized into “Deficient” (< 30 ng/mL) and “Sufficient” (≥ 30 ng/mL). IBM SPSS v.29 was utilized to conduct data analysis.

Of the 647 patients, 192 had documented Vitamin D values. Analysis revealed Vitamin D Deficiency was more commonly seen in African Americans (p < 0.001), in those with a subacute rather than acute presentation (p = 0.016), in sicker patients [e.g, SOFA score >3 and APACHE 2 score >10 (p = 0.013), higher opening pressures (p = 0.016), and higher proportion of obtundation where Glasgow Coma Score <13 (p = 0.035)], and in patients more likely to be readmitted (p = 0.015). Vitamin D Deficiency was not associated with worse clinical outcomes.