I like this post. And it's a very good question.

I believe that every individual has different dietary needs. E.g. a Body builder has far more protein requirement than a pregnant woman, a child, a stressed worker.

If food is sourced properly, cooked properly - and I hate to say it, but nutrients ARE destroyed when cooked. Not all, and not all the time, but some nutrients are not as stable to heat/light than others. There was a great study done by horticultural scientists at the Uni of California that supported the theory. This makes sense, because HEAT acts as a catalyst for reactions, and that reaction is degradation of nutrients. Best advice is to source fresh fruit and veg, and to consume within a few days. I don't cood my veg on the stove top, but rather in a controlled cooker where I can control the temperature.

Having said this, I do take a multivitamin and fish oil capsules. I don't eat enough fish in my diet, so I do consume the supplements. But if I ate more oily fish, I wouldn't need the capsules. The multi I take b/c I know I lack some essential B vitamins in my diet.

Generally, we should be able to get what we need from food, the problem is... we don't. Either due to poor dietary choices, or lack of nutrients in the foods. The question for me is, if we were able to get what we need from food, would we ever get sick?