You do need supplements
While I don't take protein supplements or anything to gain mass, it is imparitive that you take a quality multivitamin supplement. Not a one a day from the local drug store or even a brand name like Centrum.
I take a multivitamin, extra calcium/magnesium, omega-3 and CoEnzyme Q10. All of these keep our bodies running at optimal health levels and aid in muscle recovery. Plus it's not a bad bonus that you never get sick because your immune system is so strong.
So if you are looking to gain mass I would say extra protein is a good idea, but not imparitive. If you are looking to be healthy and feel good, try some quality supplements.
Best wishes,
Mike