= 35%). In subgroup analyses, inverse associations were observed in both premenopausal and postmenopausal women, across shorter and longer follow-up periods, and in European and American cohorts. Dietary calcium intake, alone or combined with supplements, was associated with a reduced risk, whereas supplemental calcium alone was not. These findings suggest that higher calcium intake, particularly from dietary sources, may modestly reduce breast cancer risk. Further research is needed to confirm causality and clarify mechanisms.
Karimi et al. (Sat,) studied this question.