Interesting post - and great blog! I like how this other Paul - Paul Whiteley - both links to and summarizes the controlled studies and other resources relevant to his posts. In this one, he quotes a study showing those with the lowest Vitamin D levels had the highest suicide rates/risk.
Don't know so much about lithium, and what municipal water it may or may not be in. Though I did taste the Lithia water in Ashland, Oregon that is supposed to have amazing healing qualities. It smelled of sulfur and was too mineral tasting for me. Don't know that it did much for me, either.