Investigating vitamin D and its analogues as potential treatment hemotherapy-induced gastrointestinal (GI) mucositis, a common and debilitating side effect of cancer therapy that causes inflammation, ulceration, and disruption of the gut lining. The research examines whether vitamin D can reduce inflammation, promote mucosal healing, and improve gut microbiome balance. Using animal models. the study analyses intestinal tissue damage, microbiome composition, inflammatory markers, immune responses, and mucin gene expression following chemotherapy treatment. The findings may support the development of novel therapies to improve patient quality of life, treatment outcomes, and long-term cancer survival.