70 years after water fluoridation began, there remains a scarcity of research investigating the toxic effect of fluoride on liver function.
We do know that fluoride exposure at levels currently deemed safe by the US Environmental Protection Agency, .7 ppm, can damage liver function in children. Altered liver function can impact bodily fluoride absorption and metabolic processes. Children drinking water with more than 2 ppm fluoride, particularly those with dental fluorosis, were found to have increased levels of lactic dehydrogenase in their blood (an indicator of liver damage).
Because of the scarcity of research on fluoride’s effect on the liver, the National Academies of Science recommended that:
“The effect of low doses of fluoride on kidney and liver enzyme functions in humans needs to be carefully documented in communities exposed to different concentrations of fluoride in drinking water.”