A study out of Belgium shows a direct correlation between vitamin D levels and survival rates in women diagnosed with breast cancer. The study looked at women’s levels of vitamin D when they found out that they had breast cancer and discovered that women with higher levels of the vitamin were more likely to survive. Women who had 30 nanograms of vitamin D per milliliter of blood were about 50% less likely to die within 5 years of their diagnosis compared to women that had levels of vitamin D that were lower. The study found that for every 10 nanogram per milliliter increase in vitamin D, women had a 20% reduction in their risk of dying over the course of the study. Researchers noted that the results held true even when other cancer survival factors were taken into account such as age and BMI (body mass index).

The researchers who performed the study were quick to note that this discovery denotes a correlation and not a directly related series of events between breast cancer and levels of vitamin D. Previous studies have tried to show that taking vitamin D supplements and increasing the level of vitamin D in
one’s diet can help prevent breast cancer, but these studies have been inconclusive.

The Role of Vitamin D

According to the National Cancer Institute, vitamin D is an essential component in the formation, growth, and repair of bones and is important for the normal absorption of calcium. The organization also notes that while associations between vitamin D and reduced cancer risk have been explored, the direct link between the two remains unclear.

According to BreastCancer.org, about one in eight U.S. women will suffer from breast cancer throughout their lives. In 2011, over 230,000 invasive breast cancer cases were expected to be reported in U.S.  women as well as over 57,000 non-invasive breast cancer cases. Currently, statistics show that more
women are diagnosed with breast cancer than any other type of cancer in the U.S. The second most common type of cancer amongst women is skin cancer.

While more research certainly needs to be done regarding the link between vitamin D and breast cancer, the study shows that the connection is certainly worth exploring and could lead to breakthroughs that may help reduce the number of women who suffer from breast cancer.