There is NOTHING like a good diet. Supplaments help a bit, but you have to do it all on your own. You also do not want the side effects of taking heavy duty supplaments. Train hard, do a lot of cardio, eat lean and healthy. A multivitamin would be good, something with a lot of B vitamins. If you are training hard, take some whey protein powder after your workouts. Gold whey standard is good and very versatile, you can also try a natural or vegan brand or something like that.