Amazing sometimes how things slip your mind....
Vitamin D shortage will exacerbate muscle and soft tissue pain. And 20 minutes in the sun daily doesn't make up for it... Have you had your D checked by blood tests?
If you're going to supplement, do it with the dry D3 (Biotech makes it, I have no interest or ties to Biotech) - or under a doctor's supervision - D2 is the form that converts to D3, and it's possible that your body does not do the conversion.
Just another thought about a possible cause and treatment.
I'm all for getting the cause under control.
alys