Short-Term Outcomes in Patients With Coexistence of COVID-19 Infection and Vitamin D Deficiency: A Large Cohort Study.

Introduction: Vitamin D deficiency (VDD) is prevalent worldwide and may influence the severity of infectious diseases, including COVID-19. This study aimed to evaluate the association between VDD and 30-day clinical outcomes in patients with COVID-19.

Methods: We conducted a retrospective cohort study using data from the TriNetX database, which includes de-identified electronic health records of approximately 155 million patients from 131 healthcare organizations globally. Adult patients (aged ≥18 years) with their first documented COVID-19 infection between January 2022 and September 2024 were included. Patients were categorized based on their vitamin D status within three months prior to COVID-19 diagnosis: those with documented VDD (VDD group) and those without (controls). Outcomes assessed were all-cause mortality, all-cause hospitalization, the requirement for critical care services, and a composite outcome of these events at 30-day follow-up. Propensity score matching (PSM) was utilized to balance covariates such as age, sex, race, and comorbidities between the groups. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox regression analysis.

Results: After PSM, the study included 68,814 patients, with 34,407 in both the VDD and control groups. VDD was associated with a slight but statistically significant increase in the hazard of experiencing the composite outcome (HR 1.05, 95% CI 1.01-1.10, P = 0.02). There was no significant difference in all-cause mortality (HR 1.06, 95% CI 0.92-1.22, P = 0.42) or all-cause hospitalization (HR 1.01, 95% CI 0.96-1.05, P = 0.80) between the groups. However, patients with VDD had a significantly higher hazard of requiring critical care services compared to controls (HR 1.28, 95% CI 1.16-1.41, P < 0.01).

Conclusion: Vitamin D deficiency is associated with an increased risk of requiring critical care services among COVID-19 patients, suggesting that VDD may contribute to greater disease severity. These findings underscore the potential importance of assessing and managing vitamin D deficiency in patients with COVID-19 to improve clinical outcomes.