Vitamin D supplementation can improve the 28-day mortality rate in patients with sepsis-associated acute kidney injury

Abstract

Purpose Vitamin D levels are generally lower in septic patients and are associated with poor prognosis. Observational studies suggest improved renal recovery in acute kidney injury (AKI) patients with increased vitamin D levels. Still, large RCTs did not show significant clinical benefits, possibly due to the limited number of sepsis or AKI patients included. This study aimed to examine the impact of vitamin D supplementation on 28-day all-cause mortality in patients with sepsis-associated acute kidney injury (S-AKI).Methods A retrospective cohort study was conducted using data from the MIMIC-IV (v2.0) database, which included 18,713 ICU patients with S-AKI. Propensity score matching (PSM) was used to adjust for confounding factors, and multivariate Cox regression was employed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Patient survival and clinical characteristics will be assessed utilizing Kaplan–Meier curves, with comparisons conducted using the log-rank test.Results Kaplan–Meier survival analysis revealed significant differences in survival between the groups. Multivariate Cox regression indicated a reduced risk of 28-day mortality associated with vitamin D supplementation (HR: 0.73, 95% CI: 0.67–0.80, p < 0.001). The results after PSM were consistent with those of the original cohort. Similar results were observed for in-hospital mortality and 90-day mortality. The Restricted Cubic Spline curve (RCS) indicated an increasing trend in the therapeutic effect of vitamin D with increasing SOFA score.Conclusions Vitamin D supplementation is associated with decreased all-cause mortality in patients with S-AKI, and those with more severe conditions may benefit even more.

Keywords

• Intensive care unit
• sepsis
• AKI
• vitamin D
• MIMIC-IV