The Vitamin D council has some recommendations on doses. Here's a link http://www.vitamindcouncil.org/about-vitamin-d/how-to-get-your-vitamin-d/vitamin-d-supplementation/
Based on the body's indicated daily vitamin D usage, Vitamin D Council recommends the following amounts of supplemental vitamin D3 per day in the absence of proper sun exposure. Due to the variable response discussed above, these are only estimated amounts.
•Healthy children under the age of 1 years – 1,000 IU.
•Healthy children over the age of 1 years – 1,000 IU per every 25 lbs of body weight.
•Healthy adults and adolescents – at least 5,000 IU.
•Pregnant and lactating mothers - at least 6,000 IU.
Additionally, children and adults with chronic health conditions such as autism, MS, cancer, heart disease, or obesity may need as much as double these amounts.
also...
At the IOCDF conf. in Chicago, Dr. Murphy mentioned D (with respect to PANDAS). She said:
"Vitamin D is immune modulating and anti-microbial. 50 is an ideal level."
Btw, I also have in my notes the words "Swedish D study"...I don't know what she meant but I googled and found this:
http://www.vitamindcouncil.org/news-archive/2010/update-on-autism-and-vitamin-d/
At the same time, some researchers in the USA continue to deride my theory while scientists in Sweden are starting to piece it together. Three Swedish papers were published this month that support the Vitamin D Theory of Autism.
It makes sense that low D could be a piece in the rise of autism puzzle. 1-2 generations ago, people probably spent more time outside, and were not quite so fanatic about sunscreen.