HealthDay News — Sufficient circulating concentrations of vitamin D may protect against breast cancer in Hispanic/Latina women, according to a study published online April 25 in Cancer.
Katie M. O’Brien, Ph.D., from the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, and colleagues examined the association between vitamin D levels and breast cancer among 290 Black/African American and 125 non-Black Hispanic/Latina women participating in the national Sister Study cohort.
The researchers found that during a mean follow-up of 9.2 years, women with circulating 25-hydroxyvitamin D (25[OH]D) concentrations above the clinical cut point for deficiency (>20.0 ng/mL) had lower breast cancer rates than women with concentrations ≤20 ng/mL (hazard ratio, 0.79; 95 percent confidence interval, 0.61 to 1.02). Among Hispanic/Latina women, the inverse association was stronger (hazard ratio, 0.52; 95 percent confidence interval, 0.29 to 0.93), and the association was weaker among Black/African American women (hazard ratio, 0.89; 95 percent confidence interval, 0.68 to 1.18; P for heterogeneity = 0.13). Results did not differ by menopausal status, follow-up time, estrogen receptor status, or invasiveness. There was no independent association seen between either 24,25(OH)₂D or the 24,25(OH)₂D-to-25(OH)D ratio and breast cancer risk.
“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 statement. “However, questions remain about whether these associations are truly causal and, if so, what levels of vitamin D are most beneficial.”