You do need minerals, and during most of our time on Earth, we got most of our minerals from water in the streams and lakes. You do get minerals from food also, of course (read labels). But if you take mineral supplements, you get specific kinds and amounts of the minerals you WANT and not other minerals that you don't want, don't need, and in some cases shouldn't be ingesting at all. If you take minerals as part of your supplement regimen, you don't need minerals in your water. (If you DON'T get minerals from SOMEWHERE, then distilled water isn't the way to go). We've been drinking distilled water for decades, our health is good and our bi-annual blood tests show we have appropriate levels of minerals in our bodies.