Insufficient vitamin D may play a role in breast cancer, especially among minority women, new research indicates.
Black and Hispanic American women with low vitamin D levels have a higher risk of breast cancer than those with sufficient vitamin D levels, researchers found.
The findings suggest that vitamin D may help protect these groups of women against breast cancer, according to the researchers.
The study was published online April 25 in the journal Cancer.
"Together with prior studies on this topic, this article suggests that vitamin D may be associated with reduced risk of breast cancer, including among women who self-identify as Black, African-American, Hispanic or Latina," said study co-author Katie O'Brien, of the U.S. National Institute of Environmental Health Sciences.
"Because women who identify as members of these groups have lower vitamin D levels, on average, than non-Hispanic white women, they could potentially receive enhanced health benefits from interventions promoting vitamin D intake," O'Brien said in a journal news release.
"However, questions remain about whether these associations are truly causal and, if so, what levels of vitamin D are most beneficial," she added.
Previous studies have suggested that vitamin D may protect against breast cancer, but few have examined how race or ethnicity affect this association.
To learn more, the researchers analyzed blood samples from 290 Black and 125 Hispanic women who later developed breast cancer. The also took samples from 1,010 Black and 437 Hispanic women who did not develop breast cancer.
Over an average follow-up of nine years, women with sufficient vitamin D levels had a 21% lower breast cancer rate than women with vitamin D deficiency.
The link between vitamin D and breast cancer risk was strongest among Hispanic women, who had a 48% lower rate of breast cancer if they had sufficient vitamin D levels.
Black women had an 11% lower rate of breast cancer if they had sufficient vitamin D levels, according to the study.
The research only found an association rather than a cause-and-effect link between vitamin D and breast cancer.
For more on vitamin D and cancer prevention, see the U.S. National Cancer Institute.
SOURCE: Cancer, news release, April 25, 2022