Adding fluoride to water has always seemed weird to me, since you can't control for how much water someone is drinking or account for different bodily factors like age and weight. I wonder why the European solution of adding it to salt isn't the default, especially given that iodized salt is already so popular and commonplace. As a general rule of thumb, I think it's interesting to scrutinize dosage recommendations a…
No, fluoride must not be added to any food or beverage, because it provides no benefits whatsoever when ingested. Fluoride is beneficial only when applied externally on the dental enamel, so that the fluoride ions will passively substitute the hydroxide ions. There is no known biological process that uses actively fluoride in the human body and excessive ingested fluoride has bad effects, e.g. bone damage. Therefore…
It isn't mandated by law in the USA. All water contains some naturally occurring fluoride, some localities choose to add additional fluoride to their water in the USA but certainly not all. I'm pretty sure it is added in something like 60% of city water supplies.