Researchers from University of California, San Diego analyzed five past studies of breast cancer patients, accounting for 4,443 people. Women with a greater chance of surviving breast cancer had an average vitamin D level of 30 nanograms per milliliter, while the women who had less chance of surviving had an average of 17 nano grams per milliliter.
Unfortunately, most newly diagnosed breast cancer patients are at the deficient end of the spectrum.
In fact, women with high levels of vitamin D were more than twice as likely to survive breast cancer than women with low levels of vitamin D. (Study published in the Journal of Anticancer Research)