Eosinophilic esophagitis (EoE) is an immune/antigen-mediated, progressive fibrostenotic disease characterized by symptoms of esophageal dysfunction and abnormal eosinophilic infiltration in the esophagus. Despite current treatment modalities of dietary antigen elimination or topical corticosteroids, a subset of patients do not have clinical or histologic response. Even with resolution of superficial epithelial eosinophilia, patients may still have progressive subepithelial fibrosis, which may lead to esophageal strictures over time. Histologic identification of subepithelial fibrosis requires deep esophageal biopsies, which are not routinely obtained. Herein, we review the challenges in diagnosing and treating fibrosis in EoE. We propose the novel concept of vitamin D supplementation to treat fibrosis in EoE through downregulation of profibrotic mediator, transforming growth factor-beta.