I have always been taught that when you cook vegetables, the vitamins and minerals will reduce in potency. So I would say we benefit the most from raw vegetables. Quite often we forget that some vegetables, like carrots and potatoes have the most value in their skins and yet we peel that away and chuck it like garbage. I suppose the important stuff found in those jewels of veggies begins to breakdown under heat, like cooking. However, if you are making soup with fresh veggies, know that some of the good stuff is melding into the broth, so drink up!