Abstract
BACKGROUND: Despite advancements in breast cancer (BC) diagnosis and treatment, it continues to be a serious health concern among women due to its high incidence rate. Thus, prevention strategies in BC are essential. Some nutrients such as vitamin D may play a preventive role against BC through different genes which have a vital role in several pathways. These pathways include autophagy, tumorigenesis, apoptosis, immunity, and genome stability. This study aimed to review the role of vitamin D in BC via the network of vitamin D-regulated pathways. METHODS: This systematic review was conducted following PRISMA guidelines. PubMed, ScienceDirect, and Scopus were searched using a combination of MeSH terms and keywords related to molecular and cellular mechanisms of the effects of vitamin D on breast cancer. A total of 200 articles were initially found, from which 14 relevant studies were selected based on specific inclusion and exclusion criteria. RESULTS: Experimental studies have shown possible anti-carcinogenic effects of vitamin D-related genes due to their participation in regulating autophagy, tumorigenesis, apoptosis, immunity, and genome stability in normal and malignant breast cells. Moreover, vitamin D deficiency has the potential to create a supportive environment that promotes proangiogenic processes, tumor cell dissemination, metastasis, and establishment at secondary sites. CONCLUSION: Vitamin D may have systematic roles against BC in humans through various interactions with different genes, which have roles in different and important pathways as underlying mechanisms in the pathophysiology of BC. More broadly, research is also needed to determine the exact protective effect of vitamin D on BC risk.