Effects of Vitamin D Supplementation on Recurrence of Nasal Polyposis after Endoscopic Sinus Surgery

INTRODUCTION: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a relatively common disease with serious impacts on patient quality of life. Recurrence of polyps after functional endoscopic sinus surgery (FESS) is a dilemma. Vitamin D3 (VD3) is known to inhibit the proliferation of nasal polyp-derived fibroblasts. The present study aimed to investigate the effects of oral VD3 on the recurrence of polyposis after FESS. MATERIALS AND METHODS: This triple-blind placebo-controlled clinical trial was conducted on 40 patients with CRSwNP who did not respond to medical treatment and were candidates for FESS. In addition, the patients had VD3 insufficiency. Following the surgery, all the patients received routine treatment (i.e., fluticasone spray, irrigation, cefixime 400 mg daily for 10 days, and montelukast for a month). Moreover, the case group received oral VD3 tablets 4000 IU (single daily dose) for a month, and the control group received placebo in the same manner. The Sino-Nasal Outcome Test (SNOT-22) and Meltzer endoscopic grading scores were recorded at months 1, 3, and 6 after the study. RESULTS: In this study, 6 months following the intervention, the severity of polyposis was reported to be significantly lower in the VD3 group compared to the placebo group based on SNOT-22 (16.25±10.16 in the VD3 group vs. 47.45±13.55 in the placebo group; P<0.001) and Meltzer scores (0.50±0.60 in the VD3 group vs. 2.65±0.93 in the placebo group; P<0.001). No adverse effects were observed in the case group. CONCLUSION: This study showed the efficacy and safety of vitamin D supplementation in the reduction of polyposis recurrence after FESS in patients with CRSwNP.