The following video narrated by Mike Adams (Natural News) is worth watching, especially if your water is fluoridated and your water company has convinced you it is harmless and helps prevent cavities.
To understand that fluoride is one of the most toxic poisons on the planet, you need to understand how fluoridation of water came about in the first place. Sodium fluoride is a by-product of the aluminum and fertilizer industries---a toxic waste called silicofluoride that contains arsenic, cadmium, lead, and other toxins. Instead of paying to dispose of this toxic waste, the aluminum and fertilizer industries came up with a plan---sell it for use in public water supplies to prevent tooth decay. So what did they do? They had studies performed to show improvements in dental health as a result of fluoridated water. Yes, that's right. Two chemical companies decided you should have chemicals in your drinking water. There have been no independent studies to prove otherwise. Although there were many opponents, including many doctors (and still are) who believed fluoride in water will cause cancer, dementia, bone weakness, gastrointestinal problems, thyroid, dysfunction, and a host of other health problems, about 66 percent of the drinking water in the United States is fluoridated as of 2014.
Another tidbit you might want to know about water fluoridation. Hitler added it to the water supplies in Jewish neighborhoods to pacify them. Why? Because Hitler knew that fluoride would dull the brain, lower IQ, and make them followers.
So what can you do? If you have fluoridated water (call your water company), filter the water you drink. In my opinion, you should filter your water anyway. You cannot trust any company to your health. They care more about their profits. Just look what happened to the people in Flint, Michigan.
Make sure you buy a water system that filters out fluoride---not all do. The better water systems will start at around $200. However, their filters usually last much longer than cheaper systems. Below are some of the better systems. If you purchase a Berkey system, go directly to their website because they offer a lifetime guarantee when purchasing directly from them.