Vitamin D deficiency is common in kidney transplant recipients, but is not associated with infections after transplantation.

The relevance of vitamin D for infections after kidney transplantation is poorly defined. 25-OH vitamin D (25-OHD) levels of 135 kidney transplant recipients, enrolled in the Swiss Transplant Cohort Study, were determined peri-transplant and 6 months post-transplant. Logistic regression was used to address the associations of 25-OHD and overall infections and bacterial infections, respectively. For the first 6 months post-transplant, 25-OHD peri-transplant, and for the second period (after 6 to 30 months post-transplant), 25-OHD at 6 months post-transplant was considered. Vitamin D deficiency was common peri-transplant and remained highly prevalent 6 months after transplantation despite frequent supplementation. Median 25-OHD levels increased from 12.0 ng/mL (IQR 5.3-19.5) peri-transplant to 16.5 ng/mL (IQR 10.6-22.6) 6 months post-transplant (P = .005). We did not detect a significant association between 25-OHD and overall infections (adjusted odds ratio (aOR) 1.05, 95% confidence interval (95%CI) 0.44-2.51; aOR 0.67, 95%CI 0.31-1.43) or bacterial infections (aOR 0.79, 95%CI 0.32-1.96; aOR 0.79, 95%CI 0.35-1.75) for the first and second period. To conclude, at both time points, vitamin D deficiency was observed in more than 50% of kidney recipients, albeit an increase in 25-OHD in the longitudinal course was observed. No significant association between 25-OHD and infections was detected.

Vitamin D status and risk of infections after liver transplantation in the Swiss Transplant Cohort Study.

Increasing evidence indicates a role of vitamin D in the immune system affecting response to infections. We aimed to characterize the role of vitamin D status, i.e. deficiency [25-OH vitamin D (25-OHD) <50 nmol/l] and no deficiency (25-OHD ≥50 nmol/l) in incident infections after liver transplantation. In 135 liver transplant recipients, blood samples drawn at time of liver transplantation and 6 months afterwards were used to determine 25-OHD levels. Incident infections episodes were prospectively collected within the Swiss Transplant Cohort Study database. Poisson regression was applied to address associations between vitamin D status and incident infections. Vitamin D deficiency was common at time of transplantation and 6 months afterwards without a significant change in median 25-OHD levels. In univariable analyses, vitamin D deficiency was a risk factor for incident infections in the first 6 months post-transplant incidence rate ratio (IRR 1.52, 95% CI 1.08-2.15, P = 0.018) and for bacterial infections occurring after 6 up to 30 months post-transplant (IRR 2.29, 95% CI 1.06-4.94, P = 0.034). These associations were not detectable in multivariable analysis with adjustment for multiple confounders. Efforts to optimize vitamin D supplementation in liver transplant recipients are needed. Our data question the role of vitamin D deficiency in incident infections.