For <i>non-</i>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 <i>and</i> 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 ...<p>Vs. fluoride always seems to be a raging culture war.<p>Why?