Several studies assessed the association of Vitamin D with mammographic breast density, a known and strong breast cancer risk factor.
Mammographic density is a strong risk factor for breast cancer, but the underlying biology for this association is unknown. Studies suggest that vitamin D may.
Supplementation with vitamin D3 in premenopausal women may not have a significant effect in decreasing breast density percentage.
Showing that vitamin D reduces breast density would provide strong support for the idea that vitamin D can be a safe and inexpensive.
This study reports on the relation of dietary vitamin D and calcium to mammographic breast densities, one of the strongest breast cancer risk.