By:  Igor Bendik

Can nutrition play a role in decreasing the risk of breast cancer?

Breast cancer is the most prevalent cancer in women globally. According to the World Health Organization (WHO), the diagnosis of breast cancer is growing in the developing world, due to increased life expectancy, increased urbanization and adoption of western lifestyles^.1 A new study suggests higher vitamin D levels are associated with lower risk of breast cancer progression and mortality^.2   

1,666 women diagnosed with breast cancer took part in the study. The findings showed that the women’s 25-hydroxyvitamin D serum levels were independently associated with better outcomes, including overall survival. Compared to women with low vitamin D levels, those with higher levels had reduced risks of all-cause death. The associations between higher vitamin D levels and more positive results were even stronger in premenopausal women.   Several previous studies have examined the association between vitamin D blood levels with breast cancer survival outcomes. Out of ten studies, five reported superior overall survival in patients with higher vitamin D levels ^3-7, four reported significant outcomes, while one resulted nonsignificant after adjustment.⁸ The findings of the most recent study are consistent with the majority of the studies demonstrating better overall survival among patients with higher vitamin D levels. This association was also confirmed in two meta-analyses published in 2014.⁹¹⁰ An earlier systematic review commissioned by the Institute of Medicine helped establish mortality being possibly inversely related to vitamin D blood concentrations in cancer patients.¹¹   

The new data provides compelling evidence for inverse associations between vitamin D serum levels and risk of breast cancer progression and death, and that the relationship between serum vitamin D level and cancer survival may be linked. To conclusively demonstrate this association however, randomized clinical trials using vitamin D supplementation and placebo are necessary.

A recent study on consumer health concerns conducted in Europe, revealed that over 40% of adults are concerned about protection against diseases later in life. At the same time, awareness about the important role diet and nutrition play for prevention (50%), and the positive association of vitamin D for health (76%) are relatively high.