Folate in pregnancy has been a thing forever. Folate reinforced foods, commonplace. Precisely because of neural tube development in pregnancy. I would add, across the period of time diagnosis of autism has risen, folate supplementation has been commonplace.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4933077/ for example.

I'm not an epidemiologist. I prefer advice on things to come with epidemiologists backing. I'm not getting a vibe if that's happening this news cycle.

in other words, vitamin B9