Re: To Corinthian
"it seems to be difficult to get the required amounts from foods directly"
This statement is key... I suspect, with attention to high quality, seasonal local grown foods, we would all be able to improve our health considerably without much more than an occasional cleanse and herbs used in food preparation for the most part.
Food processing is one of the many ways manufacturers squeeze profit out of a product. Instead of providing the consumer with one, unrefined, whole food product that may have some benefit to it, the consumer is provided with, and purchases, the nutritionally void processed food, and then the supplements that should have remained in the food in the first place, derived from the same food already payed for once.
In all honesty, as consumers, we asked for it, did we not?
Convenience... even just preparing meals at home from scratch (no prepackaged foods) and forgoing meals away from home (take your lunch to work) will help almost everyone to improve their health.