Vitamin D affects breast cancer outcomes for women of color, study finds

26 Apr 2022 --- Higher vitamin D levels are associated with lower breast cancer rates among women of color, according to a new study of Black and Latina women. The findings are expected to impact nutrition advice and medical recommendations.

Vitamin D has a demonstrated relationship with cancer of all forms:

“In the US, women who self-identify as Black/African American or Hispanic/Latina have lower circulating vitamin D levels, on average, than non-Hispanic white women,” Dr. Katie O’Brien, researcher for the study, tells NutritionInsight.

“Therefore, if vitamin D can help protect against breast cancer or any other adverse health outcomes, women from these racial or ethnic groups may receive greater overall health benefits from interventions to increase levels.”

Non-Black Latina women had the highest association between rate of breast cancer and vitamin D levels.The study did not aim to establish daily recommended values, she explains.

Anti-carcinogenic effects
Within scientific literature, there has been an established connection between vitamin D and cancer incidence and aggressiveness prior to the study. 

“Cell-line and animal-based laboratory studies have demonstrated that vitamin D has anti-carcinogenic effects, but it is unclear whether that translates to protection against breast or other cancers in humans. In terms of breast cancer specifically, clinical trials have failed to show that vitamin D supplementation protects against the disease,” O’Brien explains. 

She continues that clinical trials have limitations: “However, we believe the association between vitamin D and breast cancer deserves further study, including a more in-depth consideration of the role of race and ethnicity.”

“Our study does not specifically address questions about what intake levels may be needed to prevent breast cancer and the findings can only be considered in conjunction with the results of many other studies of vitamin D and health.” 

“That being said, our study does provide further evidence that vitamin D may protect against breast cancer, and therefore is generally supportive of consuming enough vitamin D to maintain sufficient circulating levels.”

Assessing impact on demographicsDr. O'Brien affirms that research on health outcomes for different ethnicities can make health science more robust.
While elaborating on the study, O’Brien affirms that demographic-specific medical research is imperative to ensure better health outcomes for different groups.

“In this particular case, we also wondered if racial or ethnic differences in circulating vitamin D levels might help explain why Black and African American women are more likely to have more aggressive forms of breast cancer.” 

“This hypothesis was ultimately not supported by our results, which showed no difference in the association between vitamin D and the considered breast cancer subtypes.” 

She goes on to say that it is “especially important” to consider race or ethnicity-specific estimates when there are established disparities in both exposure and outcome “as doing so may offer additional clues to understanding disease etiology.”

“We continue to be interested in the association between vitamin D and breast cancer, and in better understanding the role played by race or ethnicity. We have plans to follow-up this work with studies that additionally consider some of the genetic and epigenetic factors involved.”

Recently, the UK has looked at boosting the health of its population via vitamin D supplementation. Countries like Switzerland are also mulling over such a move, with Finland having taken the step of mandatory vitamin D fortification with great success.

By Olivia Nelson