The body is perfectly capable of maintaining its own pH balance provided it receives the proper nutrients. When the body is not getting enough alkaline minerals from food and water, it must rob calcium from its own bones to neutralize acidity. This is not ideal and once the body's readily available alkaline mineral supplies are depleted, it becomes overly acidic. It is important to note that water can be either naturally alkaline or artificially alkaline. Why? Naturally alkaline water contains the alkaline minerals the body needs to combat acidity. Artificially alkaline water, such as water from a typical alkaline water ionizer machine, has a pH that is artificially increased and does not have any more alkaline minerals than the original water used to supply the machine. Artificially alkaline water has also been proven to cause side effects, and from a chemical perspective, such a water cannot be found anywhere in nature.
"Eat what Nature provides. Whenever people have attempted to 'improve' on Nature, they go wrong. - Wallace D Wattles
Artificially alkaline water is completely neutralized in the stomach and offers the body no additional alkaline minerals to combat acidity. Only naturally alkaline water has the minerals the body needs to combat acidity and build its acid buffering reserves. When drinking artificially alkaline water continuously, side effects can develop. To read more about the two types of alkaline water and the side effects of consuming artificially alkaline water, please read the article Alkaline Water Exposed - What They Don't Tell You.