Vitamin D deficiency is an independent risk factor for urinary tract infections after renal transplants

Vitamin D deficiency is frequently found in patients with renal transplants (RTxs). Because vitamin D plays indispensable roles in the immune system, there may be an association between vitamin D deficiency and infection in these patients, but this has not been fully elucidated. Therefore, this study investigated the impact of pre-RTx vitamin D deficiency on urinary tract infection (UTI) development after RTx.We measured 25-hydroxyvitamin D3 (25(OH)D3) levels in 410 patients 2 weeks before they underwent RTx. Vitamin D deficiency was defined as 25(OH)D3 <10 ng/mL. The primary outcome was UTI occurrence after RTx. Cox proportional hazard analysis determined whether vitamin D deficiency was independently associated with UTI.The mean 25(OH)D3 level was 12.8 ± 6.9 ng/mL, and 171 patients (41.7%) were vitamin D deficient. During a median follow-up duration of 7.3 years, the UTI incidence was significantly higher in vitamin D-deficient patients (52 patients, 30.4%) compared with vitamin D-nondeficient patients (40 patients, 16.7%) (P = 0.001). Moreover, multivariate Cox proportional hazard analysis showed that vitamin D deficiency was an independent predictor of UTI after RTx (hazard ratio 1.81, 95% confidence interval 1.11-2.97, P = 0.02).Vitamin D deficiency was an independent risk factor for UTI after RTx; hence, determining 25(OH)D3 levels might help to predict infectious complications after RTx.