Completely agreed. My in-laws' doctor is one of the mega-dose Vitamin D people. They live in Florida and get plenty of sunshine. He's got no reason behind it, just that it'll work miracles. I know where you're coming from.
Just goes to show, as another example, that the people who probably need Vitamin D aren't getting it while my in-laws, with excellent health insurance, throw that health insurance money away pretty frequently on random things because some quack told them to.