However, the evidence to date would suggest that this is not the case. First, even in this study, even women with very high levels of Vitamin D were still diagnosed with breast cancer. The higher levels of vitamin D simply meant average longer survival. So what do I think is going on?
I believe, and a recent study, which I will discuss in a moment, supports my tentative conclusion, that this is a matter of correlation between vitamin D levels and one's state of health.. As correlation does not imply causation, raising vitamin D levels artificially high with Vitamin D supplements will neither prevent cancer, as the first study clearly showed, nor improve its prognosis. Why?