Here is one recent case controlled study testing Vitamin D status and supplementating it showing some efficacy (for 80% of the kids with low status).

http://www.ncbi.nlm.nih.gov/pubmed/25876214

There is also a Vitamin D hypothesis of ASD as well as correlation studies. Given most of the North American population is deficient in Vitamin D including my wife during pregnancy and I (using the 30ng/ml threshold), that is one simple thing that makes sense to test and supplement for all.

We used to… read more