# Vitamin D and Chronic Rhinosinusitis with Nasal Polyps: A Narrative Review and Perspectives

## TL;DR

This review explores how vitamin D might influence chronic rhinosinusitis with nasal polyps, suggesting it could play a role in inflammation and treatment.

## Contribution

The paper synthesizes current evidence on vitamin D's potential role in CRSwNP pathogenesis and treatment.

## Key findings

- Low vitamin D levels are linked to worse outcomes in CRSwNP patients.
- Vitamin D supplementation shows promise in improving symptoms in deficient individuals.
- Vitamin D may modulate immunity and epithelial integrity, possibly affecting CRSwNP.

## Abstract

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis (CRS) characterized by bilateral nasal polyps, primarily affecting adults. It is often associated with hyposmia and asthma and driven by persistent Th2 inflammation, particularly in Caucasian patients. The disease is recurrent and significantly impacts quality of life, yet its pathophysiology remains poorly understood. Management includes intranasal steroids, short courses of systemic corticosteroids, surgery for refractory cases, and biologics. However, despite these treatment options, disease control remains challenging. Low vitamin D levels have been associated with worse clinical outcomes, while supplementation studies show promise in improving symptoms in deficient patients. Emerging research suggests that vitamin D modulates immunity, fibroblast activity, and epithelial integrity, potentially contributing to CRSwNP pathogenesis, though the exact mechanisms remain unclear. This review synthesizes current research on vitamin D’s role in systemic and local inflammation in CRSwNP. By highlighting its potential therapeutic implications, this work aims to guide future research and inform clinical practice. Additionally, it may serve as a foundation for understanding the broader impact of vitamin D deficiency in sinonasal diseases and other atopic conditions.