Methods: We performed a randomized, placebo controlled trial in adult subjects meeting the research criteria for CRS, with low serum vitamin D levels (<40 ng/mL), and having no contraindications to vitamin D therapy. Subjects were randomized to receive vitamin D (n=12) or placebo (n=12) for 12 weeks in addition to their standard regimen. Peripheral blood mononuclear cells (PBMCs) and nasal epithelial cells (NECs) were collected at the beginning and end of the trial and we analyzed the upregulation of molecules involved in mucosal immunity by RT-PCR. Clinical response was analyzed using SNOT-22 and the SF-36.
Results: The Levels of vitamin D in the serum were elevated in the vitamin D group and unchanged in the placebo group. Cathelicidin, human b-defensin and autophagy related protein light chain 3 alpha (LC3A, a molecule involved in autophagy) were upregulated after vitamin D administration in PBMCs with similar results observed in NECs. There was no significant change in the upregulation of these mediators in the placebo group. No symptomatic changes were observed in SNOT-22 or SF-36 scores in either group. There were no side effects or adverse events during the study.
Conclusions: These results suggest that vitamin D might modulate mediators involved in immune responses in CRS. Further studies are needed to clarify the clinical efficacy of vitamin D in this disorder.