Vitamin D for back pain relief?

This article from Dr. Cutler.com caught my eye-----I go to a pain management specialist here in Charlotte (he's terrific, Dr. Mark Hines if anyone in this area ever needs that type of doctor) and I was going over my list of vitamins with Dr. Hines one day (I do not put any supplement in my mouth that at least one of my two doctors---Dr. Hines or Dr. Carr in CA approve). We got into a discussion about Vitamin D, and he said that an article he had just read in a physician journal stated that over 70% of chronic pain patients are Vitamin D deficient. I'm not one of them, as I take 5000 IU's daily, and I have been taking that dose for about 3 1/2 years. I do think it has helped with muscle pain, I am not stiff in the morning like I used to be. As always, check with your own health care practitioner.