A new study published in the journal Anticancer Research has found that high vitamin D levels may be related to a lower death rate in patients with breast cancer.
Breast cancer is very common among women. In the United States in 2013, there were roughly 234,580 new cases diagnosed and 40,030 deaths from breast cancer. In 2012, there were an estimated 1.7 million new cases and 500,000 deaths worldwide from breast cancer.
Vitamin D may play a role in cancer through its ability to bind to cancer cells and help tell them to stop spreading, stop growing, or to die.
Researchers recently reviewed many studies to find a relationship between breast cancer death rates and vitamin D levels.
The research team looked at a total of 77 studies on breast cancer and vitamin D. They only included studies that looked at risk of death from breast cancer in which they could group study participants into four groups of vitamin D levels from lowest to highest, called quantiles.
They found five studies to meet this criteria. Out of the 5 studies, 3 of them showed that patients in the highest quantile had significantly lower number of deaths compared to those in the lowest quantile. The highest vitamin D levels had a 44% lower death rate compared to patients with the lowest levels.
“Higher serum [vitamin D] concentrations were associated with lower fatality rates in patients with breast cancer,” the researchers concluded. “Patients with the highest concentrations of [vitamin D] had approximately half the fatality rate compared to those with the lowest concentrations.”
The researchers call for future studies looking at the effects of vitamin D supplementation on breast cancer mortality to see if these results are directly due to vitamin D levels.