Right now, I'm trying to get a blood test for Vitamin D, but all the doctors I've gone to see are ignorant of the latest Vitamin D research, and don't see the value of doing the test. If I can't find a doctor who will authorize it in the next year or so, then I'm probably going to drive down to the US and pay cash using Direct Labs (http://www.directlabs.com/) or the Life Extension Foundation (http://www.lef.org/). It's terribly inefficient but I don't see any way around it.