alt Hacker NewsI don't know, the study seems pretty mild in findings and the research doesn't mention anything about the socioeconomic environment in which each of the children grew in.
Maybe it's the high dose vitamin, maybe it's because one cohort was skewed one way on the socioeconomic spectrum, maybe it's something else entirely. More evidence would be needed imo to confirm Vitamin D3 has a direct contributor to cognitive performance as the research portrayed.
> the research doesn't mention anything about the socioeconomic environment in which each of the children grew in.
The main trick behind randomized control trials is that you can disregard factors like this because these effects would be randomly distributed as well.