This is a water myth that is widely misunderstood. There are four reasons why you don’t need the minerals found in water…
1) The minerals are not in a form that is useable by the body. So let’s take a look at how minerals get into water. Pure rain water falls to the ground and dissolves some of the minerals that it touches, thus these minerals are from an inorganic source; rocks. Humans and animals are simply not designed to get our minerals from rocks. You can’t suck on a rock of calcium and get much benefit. Humans and animals get our minerals from plants, or animals that have gotten their minerals from plants. These minerals are called “bioavailable”, or “chelated” and they come from an organic form. Look at your ingredients on any good mineral supplement, for example, and it will say that it’s from “calcium citrate” or some other organic form. Basically, eat a balanced diet of fruits and vegetables and nuts and meats, because this is where we get minerals. Dr. Andrew Weil says this, "We get our minerals from food, not water."
2) There can be harmful minerals in water. All minerals are not good for you. There are many parts of the country that have high levels of arsenic or nitrates, which have both been linked to many different forms of cancer.
3) Whatever minerals are in the water are often mixed with other chemicals. There are over 85,000 chemicals registered with the EPA, and an increasing amount are being found in our water supplies. So even if you could get good minerals from water, it would be like dropping a vitamin on the ground and getting it all dirty before you take it. You simply don’t know what other bad stuff is in the water.
The quantities are too small. Anyone who still thinks that they want minerals in their water has to consider that they would have to drink a ridiculous amount of water to get anywhere close to the recommended Dietary Allowance of minerals in their diet. If you live in Boston, for example, you’d have to drink over 650 glasses of water each day just to meet the Recommended Dietary Allowance. This view is backed up by The American Medical Journal that states, “The body’s need for minerals is largely met through foods, not drinking water.”