"I've kind of just learnt to let these kinds of things people say (who haven't spent as much as an hour of their life reading about health) just slip in one ear and slip out the other one just as quickly..."
I've found the correct response to this kind of idiocy a long time ago. I simply challenge the person to a one mile race. I tell them that, after one mile, we will find out the real truth of who is depleted of minerals, and who is not.
So far, I've never had anybody accept my challenge.