May have been posted here before, but adding on to the subject...
Archives of Neurology - Prevalence of Vitamin D Insufficiency in Patients With Parkinson Disease and Alzheimer Disease
Archives of Neurology - Vol. 65 No. 10, October 2008
EDITED to add: I really like to real the full text before suggesting an article, but unfortunately at this time I am unable to get that. I can only get the abstract, but it caught my eye. *eye *eye