Mise en place- Is there a loss of nutrients?

I'm having chinese tonight, and while I was cutting up my bell pepper, green onions, garlic, ginger and mushrooms earlier today, I wondered if there is any loss of nutrients due to Mise en place? I know every restaurant in the world does this, so it can't be too bad can it? I've always heard/read that when you pick vegetables from your home garden, you should use them right away to prevent any loss of vitamins.