The effect of domestic water filters on water fluoride content.

The effect of filtration on water fluoride level was investigated in a study using commercially available filters. Testing was carried out in London (low fluoride), Braintree (optimum fluoride, naturally occurring) and Birmingham (optimum fluoride, artificially adjusted). It was found that none of the filters removed fluoride. In Birmingham, but not in either Braintree or London, there was a small, clinically insignificant increase in fluoride levels with filtration using two of the five filters. It is concluded that the water filtration systems tested will not affect the advantage offered by optimum water fluoride levels. Fluoride dietary supplements should not be prescribed for children living in optimal fluoride areas, irrespective of whether they use household filters.