It would be very hard to eat a diet perfectly optimized to provide sufficient levels of all vitamins and minerals every day.
I don't care how perfect a diet you eat you should take a multi-vitamin and preferably also fish oil and vitamin c, e and some other shit.
Creatine is a no brainer because it works and has assloads of research and studies backing it.
As an example on vitamin c a couple of the foremost experts on vitamin c supplementation recommend from 500mg-3grams every day optimally. The more active you are or the harder you abuse your body with smoking, alcohol, bad processed foods etc the higher end of that range you need.
In order to even get 500mg vitamin c you would need to eat about 7 oranges a day to get that.
Vitamin/mineral supplementation is very beneficial.