your study has been heavily criticized where you already posted it:

https://news.ycombinator.com/item?id=43523900

I can only assume once you see those very valid criticisms, you will update your references

Does the study not literally refute the claim that fluoride's negative impact on IQ is lacking in evidence, contrary to the original claim? What exactly do you think needs to be updated?

the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains". Your study does not show that IQ is effected at concentrations that are being added to water supplies. Just because X can result from Y levels of some substance does't mean X results from Y-n concentrations.

> the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains".

No, this is the original claim:

> but it turns out that there are a decent amount of good studies showing a link between fluoride in water and (slightly) lower IQ when pregnant mothers ingest the fluoride.

Then the parent replied that this IQ link is lacking evidence, which it's not, per the meta-analysis I cited.

The meta analysis you linked ( https://jamanetwork.com/journals/jamapediatrics/fullarticle/... ) specifically denies any noticable associations with fluoride at the levels recommended in countries that add fluoride to water.

  For fluoride measured in water, associations remained inverse when exposed groups were restricted to less than 4 mg/L or less than 2 mg/L but not when restricted to less than 1.5 mg/L

  There were limited data and uncertainty in the dose-response association between fluoride exposure and children’s IQ when fluoride exposure was estimated by drinking water alone at concentrations less than 1.5 mg/L.

The meta analysis you linked gets the strongest results in areas of the world with outstandingly high levels of fluoride and other elements in the ground water .. water with so many additives it rings like a bell when tapped with a hammer (okay, that's an embellishment).

> specifically denies any noticable associations with fluoride at the levels recommended in countries that add fluoride to water. (Emphasis added)

Which is not a claim that was being discussed in this subthread, since the original claim being refuted specify any such qualification.