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Higher vitamin D level associated with lower risk of total cancer

Japanese study suggests beneficial effects for prevention of cancer in all sites

Japanese study suggests beneficial effects for prevention of cancer in all sites

Vitamin D can be made in the body by outdoor exposure to sunlight. Picture: iStock

The benefits of vitamin D in the prevention of skeletal disorders have long been recognised. Now, accumulating evidence suggests that these benefits may extend beyond bone health to several chronic diseases, including cancer.

Vitamin D slows the proliferation of malignant cells and exerts a pro-differentiating effect, so they look more like normal cells and grow and spread more slowly. This is done through the regulation of multiple signalling pathways arresting the cycle of malignant cell development.

The effects of vitamin D include influencing apoptosis or normal cell death; angiogenesis, which involves the formation of new blood vessels; and inflammation.

High levels of sunlight are known to correlate with lower death rates from cancer of the colon and this led to the suggestion that metabolites of vitamin D might be having a protective effect.

Optimum concentration of circulating vitamin D has previously been associated with a lower incidence of colorectal and lung cancers, but this population-based prospective Japanese study aimed to extend this knowledge by seeking an association between vitamin D concentrations and risk of cancer in all sites.

The circulating vitamin D concentrations of 3,301 people with cancer and 4,044 randomly selected other participants were measured.

Results and implications for practice

  • A higher concentration of vitamin D was associated with a reduced risk of overall cancer in men and women. There is a ceiling effect so there is no point in exceeding optimum levels.
  • The results support the hypothesis that maintaining circulating vitamin D might have beneficial effects for cancer prevention at many different sites.

Budhathoki S, Hidaka A, Yamaji T et al (2018) Plasma 25-hydroxyvitamin D concentration and subsequent risk of total and site specific cancers in Japanese population: large case-cohort study within Japan Public Health Center-based Prospective Study cohort. BMJ. 360:k671. doi:10.1136/bmj.k671.

Compiled by Ruth Sander, independent consultant in care of the older person

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