HealthDay News — Sufficient circulating concentrations of vitamin D may protect against breast cancer in Hispanic/Latina women, according to a study published online in Cancer.
Katie M. O’Brien, PhD, 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% confidence interval, 0.61 to 1.02). Among Hispanic/Latina women, the inverse association was stronger (hazard ratio, 0.52; 95% confidence interval, 0.29 to 0.93), and the association was weaker among Black/African American women (hazard ratio, 0.89; 95% 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.”