Preoperative serum 25(OH)D status and its correlation with an early endoscopic sinus surgery outcome and chronic rhinosinusitis severity.

<b>Introduction:</b> Chronic rhinosinusitis (CRS) is a long-lasting inflammatory condition affecting the sinonasal mucosa, which is likely triggered by a dysfunctional immune response. Vitamin D is recognized as an immunomodulator influencing both innate and adaptive immunity. Recently, this mechanism of action has sparked interest regarding the possible role of vitamin D in CRS pathogenesis and/or course of the disease.<b>Aim:</b> The aim of this study was to investigate the association between preoperative serum vitamin D levels and an early outcome of endoscopic sinus surgery (ESS) as well as its influence on the severity of CRS.<b>Materials and methods:</b> This prospective observational study included 25 patients with CRS with nasal polyps undergoing ESS and 18 healthy controls. The disease was confirmed clinically and radiologically. Demographic and clinical data for each subject were collected. Preoperatively, disease severity was evaluated by the patient using the Visual Analog Scale (VAS) and 22-item Sino-Nasal Outcome Test (SNOT-22), and by a researcher using the Lund-MacKay (LMS) and Lund-Kennedy (LKS) scoring systems. On the day of surgery, serum 25-hydroxyvitamin D was measured with the use of electrochemiluminescence binding assay. Six weeks postoperatively, reassessment was performed, including the VAS, SNOT-22, and LKS.<b>Results:</b> Serum 25-hydroxyvitamin D level was not significantly lower in CRS patients compared to healthy controls. Subjective and objective measures of CRS severity showed no correlation with vitamin D status. However, participants with higher vitamin D levels presented better outcomes 6 weeks postoperatively.<b>Conclusions:</b> Contradicting numerous previous studies, these findings failed to confirm the correlation between the occurrence or severity of CRS and vitamin D status. Nevertheless, vitamin D status seems to affect ESS early outcomes.