Objective: The aim of the study was to focus on the association of vitamin D and breast cancer.
Methods: The study of evidence concerning vitamin D's influence on the origin and development of breast cancer from a PubMed and individual searches.
Results: Body sunlight exposure may reduce the prevalence of breast cancer. However, these studies correspond to global populations of different countries and regions without considering other geographic factors and individual, ethnic, and cultural factors that may affect sunlight exposure. Epidemiological analyses show that low vitamin D ingestion is associated with increased risk of breast cancer. Studies measuring serum vitamin D metabolites in women who were followed many years suggest that low circulating 25-hydroxyvitamin D3 levels are associated with increased breast cancer risk.
Conclusions: Although there are controversial results, it seems plausible that sufficient endogenous vitamin D levels may have a protective function on mammary cells, reducing breast cancer risk.