Yes, I think much of the "pain" we get is circulatory. I used the amino acid arginine and citrulline this winter, because my feet seemed colder than usual. (this room does not have a heated area beneath it and on computer my feet were turning white.).

Arginine and citrulline are useful for increasing nitric acid (like Viagra does).

http://www.nobelprizewinning.com/
Dr. Ignarro also has a website:
http://www.drignarro.com/

I found however, that the arginine must have been activating my shingles pain, as I had alot of issues in my upper back and right arm, where I had my outbreak several years ago. So then I started lysine to counter that, and then it got warmer and I just stopped using them because my feet are not cold anymore!

But I'll probably do them again next winter. I am hoping the ribose will help some and maybe I won't feel the cold as much as last winter.