Potential benefits of vitamin d intake for improving outcomes in critical care patients receiving renal replacement therapy: A retrospective study based on the MIMIC-IV database

Background: Vitamin D is essential for numerous physiological functions. Earlier research has unraveled a significant correlation between vitamin D insufficiency and poor outcomes within intensive care unit (ICU) patients. Patients receiving renal replacement therapy (RRT) often experience vitamin D deficiency or insufficiency. Beyond metabolic regulation, vitamin D influences cellular biomechanics, enhancing resilience to mechanical stress and supporting tissue integrity, which are critical for ICU patients undergoing RRT. This research seeks to examine the influence of vitamin D intake on outcomes in ICU patients receiving RRT. Methods: This study examined data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. It included all adult patients undergoing RRT. The participants were grouped into two categories: administrated vitamin D throughout their ICU admission (vitamin D group) and did not administer (non-vitamin D group). In-hospital mortality (IHM) was the primary outcome measured. Kaplan-Meier (KM) method Cox regression models, and subgroup analyses were leveraged to evaluate the correlation between vitamin D intake and IHM. To strengthen the reliability of the conclusions, propensity score matching (PSM) was implemented. Results: A total of 1270 patients on RRT participated in this research, comprising 338 and 932 patients in the vitamin D and non-vitamin D groups, respectively. The KM survival curves indicated substantial differences in survival probabilities between the two categories. Following adjustments for possible confounding factors by Cox regression analysis, vitamin D intake was markedly related to a reduced likelihood of IHM (HR: 0.35; 95% [CI]: 0.19–0.63; p < 0.001). This association remained robust following propensity score matching (PSM). Further subgroup analysis exposed that vitamin D intake reduced the probability of IHM in liver disease patients. Conclusion: Vitamin D intake is independently correlated with a reduced likelihood of IHM in ICU patients undergoing RRT. Further interventional studies are warranted to validate the possible advantages of vitamin D intake in improving the health of RRT patients. This study provides robust evidence supporting the therapeutic potential of vitamin D supplementation. These findings highlight the need for personalized supplementation strategies to optimize outcomes in this vulnerable population.