Vitamin D levels have already been shown to be lower in women with breast cancer compared with healthy women, and researchers say these new results suggest that vitamin D may play a role in 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.
Vitamin D-Breast Cancer Link
They found that women with early-stage breast cancer had much higher levels of vitamin D compared with women with advanced breast cancer.
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.
The researchers say it is not known whether the lower levels of vitamin D among those with advanced breast cancer are a cause or result of the advanced cancer itself. But their findings support the hypothesis that low levels of vitamin D promote progression to advanced breast cancer.