There are many, many, forms of fluoride. However, as stated here, most fluoride is a bi-product of some industry. Does the human body use fluoride? yes, just in very small amounts. Nearly all fruits/vegatables contain a type of fluroide, but again, in small amounts, the body needs it, and, in the correct form.

Just wanted to clarify that, that there are many types of fluoride.

Reverse Osmosis filtration removes fluoride, as well as pretty much everything else.