I have been reading your questions and the responses to your water query. It is true that you will get minerals from foood - provided your eating the right foods. Also that most people need to drink 4 - 5 pints of water a day and don't but if you did, you would lose considerably more minerals if you didnt add it to the water.
One aspect that cant be ignored though is that RO or distilled water is not only demineralised, its also acidic - therefore can lower the ph of the body making it more prone to various ailments.
I can recommend clay as the ultimate re-mineraliser and re-alkaliser. Look into Terramin.