Study Finds Possible Link Between Vitamin D Intake and Breast Density

A new study found that higher intake of Vitamin D may be linked with lower breast density, which in turn can reduce the risk of breast cancer or facilitate its detection. The study, which was published in the October issue of Breast Cancer Research, found that among 157 high-risk women, breast density was inversely associated with vitamin D intake.

Study Findings

Lower breast densities reduce risk of breast cancer and make it easier to detect breast cancer via mammography. Breast density is the percentage of total breast area with a mammographically dense appearance, and is an informative marker for breast cancer risk, according to the study.

The American Cancer Society defines high breast tissue density as one of the factors that increases the risk of breast cancer. Breast tissue is primarily composed of the lobes and ducts of the milk glands (ductal tissue) and fat cells. Women with dense or "lumpy" breasts have higher percentages of ductal tissue rather than fatty tissue. This makes it more difficult to see cancerous cells on a mammogram because the ductal tissue and cancerous tissue appear similar in appearance. An annual mammogram and clinical breast exam is still the recommended method to catch early-stage breast cancer, though other technologies are being introduced.

The study, though relatively small in size, is one of the first of its kind to analyze how lifestyle habits such as diet can change breast density and breast cancer. High-risk women were defined in this study as women with a strong family history of breast cancer and/or known hereditary presence of a BRCA-1 or BRCA-2 mutation. Approximately 40 percent of women indicated this breast cancer predisposition gene. The study only examined vitamin D intake via food or supplements, and did not account for how the body naturally produces vitamin D from sunlight.