Reverse osmosis is also one of the few ways that we can take certain minerals or chemicals out of a water supply. Some water sources have extremely high levels of natural fluoridation, which can lead to enamel fluorosis (mottled teeth), or the much more severe skeletal fluorosis (an actual bending of a person's bones or skeletal frame). Reverse osmosis can filter out fluoride, or other impurities, on a large scale in a way that a charcoal based filter (like the one most commonly found in homes) can't.