foodconsumer.org - Vitamin D Theory of Autism:
"Much more interesting is the fact that children with Williams Syndrome (rare congenital disorder due to a missing piece of chromosome seven) often have greatly elevated activated vitamin D levels for several months in early life. They usually present in later life with remarkable sociability, overfriendliness, empathy, and willingness to initiate social interaction—strikingly the opposite personality of autistic children. 8 9
So, abnormally-low activated vitamin D levels produce infants with symptoms of autism while abnormally-high levels produce children with personalities the exact opposite of autism."