Vitamin D excess can lower blood levels of vitamin K2, reducing bone development. Not sure if the levels would be high enough for this (difficult to find safe numbers for in utero), but the side effects, joint pains, stiffness, could have motivated the kids to stay indoors and focus on more intellectual pursuits, leading to better cognitive performance.
I point this out because there are so many known factors both positive and negative that contribute to increased 'cognitive performance' it is impossible to account for all of them, even within a randomized trail such as this. People are weak to assumptions when it comes to correlation.
I point this out because there are so many known factors both positive and negative that contribute to increased 'cognitive performance' it is impossible to account for all of them, even within a randomized trail such as this. People are weak to assumptions when it comes to correlation.