Any cursory reading on the topic of vitamin supplements will turn up a lot of conflicting studies in regards to their health benefits. And not just on a scale between "helps you" and "does nothing", some people claim supplements will actually increase your mortality!
That's an odd turn of phrase though, "increase your mortality" that is. It's not as though mortality itself has a spectrum to it. You're either able to parish, or you aren't. It'd be more accurate to claim that it might "increase the speed of your mortality".
Is there any truth to that? No idea. I'm not the one with a PhD. Though you'd think a doctorate would leave your vernacular with a little less to nit-pick. So I don't know who to trust.