Cancer is a major public health problem worldwide which seriously threatens the life and health of humans. A large body of epidemiological evidence supports a role for vitamin D in the protection of cancer risk. The antitumor effect of vitamin D mainly comes from the binding of its active metabolites to receptors to perform related biological functions but the relationship varies depending on the location of the tumor. Meta-analysis has generally reported high vitamin D status is a protective factor for breast colorectal liver bladder and lung cancers OR= 0. 46-0. 92 . In addition the association of vitamin D-related gene polymorphisms with cancer and its impact on the relationship between vitamin D levels and the risk of cancer has also attracted great attention. Single nucleotide polymorphisms in vitamin D receptors and vitamin D synthesis and degradation pathways are associated with the risk of tumor development and progression. This article reviews the research progress of vitamin D metabolism its potential anti - cancer mechanisms and its relationship with the risk of different cancers and explores the relationship between vitamin D- related gene polymorphisms and different cancers so as to provide a theoretical basis for the primary prevention of cancer in the future.