If you eat a good diet with plenty of fruits and vegetables, then distilled water will be good for you. Only a very small percentage of the minerals dissolved in distilled water are available for the body to use at a cellular level. Most of the minerals in water are either flushed out of the body or stored in joints, blood vessels and organs.
Try drinking distilled water for three months and see how your body reacts to it. While you may not see major improvements in that short a time, you can determine if this is something that will do you good. There is a lot of controversy about drinking distilled water exclusively, but for me, it is the way to go.