One of the most important metabolic functions our body performs is maintaining the proper balance between an acidic and alkaline environment. When this balance is disrupted, illness can result. How does this happen and what can be done to prevent it? To begin, the body has an acid-alkaline (or acid-base) ratio called the pH ("potential of hydrogen," see sidebar below) that represents a balance between hydrogen cations (H+) being used to form acids and the removal of these H+, which creates alkalinity. Since many body functions happen only at certain pH levels, deviations can cause problems. For example, the immune system and a host of enzyme catalysts can only perform maximally within an exceptionally narrow pH range