Vitamin D may slow the progression of breast cancer, according to a small new study.

British researchers found that women with early-stage breast cancer had much higher levels of vitamin D in their blood than women with more advanced disease.

Vitamin D levels have already been shown to be lower in women with breast cancer compared with healthy women, and researchers say these results suggest that vitamin D may play a role promoting the progression of the disease.

Vitamin D is produced within the body in response to sunlight exposure. It is also found in eggs, liver, and fortified dairy products.

Assessing Treatments for Breast Cancer

Vitamin D-Breast Cancer Link

In the study, published in the Journal of Clinical Pathology, researchers compared blood levels of vitamin D, calcium, and parathyroid hormone in 75 women with advanced breast cancer and 204 women with early-stage breast cancer.

They found that women with early-stage breast cancer had much higher levels of vitamin D compared with women with advanced breast cancer.

The results also showed that women with advanced breast cancer had lower levels of parathyroid hormone than women with early-stage breast cancer. Calcium levels did not differ significantly between the groups.

Researcher Carlo Palmieri of Cancer Research UK Laboratories and colleagues say vitamin D boosts the activity of certain key genes and curbs activity in others. For example, laboratory tests shave shown that vitamin D treatment can speed cell death while stopping cancer cells from multiplying.

Therefore, the researchers say their findings support the hypothesis that vitamin D has a role in the progression of breast cancer.

Femara Produces Better Survival Rates

By Jennifer Warner, reviewed by Louise Chang, MD

SOURCES: Palmieri, D. Journal of Clinical Pathology, Oct. 17, 2006, online first edition. News release, BMJ Specialist Journals.