For non-ideological minerals - calcium, iron, phosphorus, potassium, sodium, etc. - there are fairly well-accepted ranges of "healthy" blood levels. And lists of undesirable side-effects, which too-low and too-high levels could cause. And plenty of medical conditions where an individual might be advised to aim for a lower or higher level. And ...
Vs. fluoride always seems to be a raging culture war.
In the US (and some other places) it's actively added to the water supply. "XYZ is doing things to our drinking water!" has always been a flash point for strong feelings, justified or not, and wild rumors, because its so fundamental and unavoidable. Combine with general skepticism against health intervention being fanned, boom.
Vs. fluoride always seems to be a raging culture war.
Why?