Impact of vitamin D deficiency on postoperative outcomes in patients with chronic kidney disease undergoing surgery: a retrospective study.

Although both chronic kidney disease (CKD) and vitamin D deficiency (VDD) are associated with increased surgical risk, their combined impact remains unclear. Using the TriNetX Analytics Network, we conducted a matched cohort study comparing postoperative outcomes in CKD patients with preoperative VDD (≤ 20 ng/mL) to those with normal vitamin D levels (≥ 30 ng/mL). The primary outcome was 30-day mortality; secondary outcomes included acute kidney injury (AKI), pneumonia, acute myocardial infarction (AMI), and atrial fibrillation/flutter (AF). After propensity score matching (21,033 patients per group), results showed that VDD was associated with higher 30-day mortality (Odds ratio[OR]: 2.33, 95% confidence interval [CI] 1.91-2.85, p < 0.0001), AKI (OR:1.94, 95% CI1.80-2.10, p < 0.0001), and pneumonia (OR:1.76, 95% CI 1.15-2.70, p = 0.0087), with no significant difference in AMI and AF. These associations persisted for 90 days. The impact of VDD on mortality and AKI was consistent across sex and CKD stages. Vitamin D insufficiency (21-29 ng/mL) showed attenuated but significant associations, suggesting a dose-dependent effect. In conclusion, preoperative VDD in patients with CKD is associated with increased risks of mortality, AKI, and pneumonia. These findings suggest the potential value of preoperative vitamin D screening and correction in patients with CKD.