摘要：Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects. ALTHOUGH VITAMIN D deficiency is known mainly for its association with fractures and bone disease, 1 – 7 its newly recognized association with risk of several types of cancer is receiving considerable attention. 8 – 11 The high prevalence of vitamin D deficiency, combined with the discovery of increased risks of certain types of cancer in those who are deficient, suggest that vitamin D deficiency may account for several thousand premature deaths from colon, 12 breast, 13 , 14 ovarian, 15 and prostate 16 cancer annually. 17 This discovery creates a new impetus for ensuring adequate vitamin D intake in order to reduce the risk of cancer.
