I did a year of MPH coursework and decided that it was a huge waste of time. The dean of admissions recommended it, but in reality you don't take anything that is very demanding of you (academically). I applied to a post bacc program and got accepted so I had to cut my ties with the MPH in order to pursue something that would actually help me get in.
It really depends on your situation though. If you're borderline competitive, I would talk to the schools you're interested in and see what they're opinion on it is (cause that's what really matters).