Some months ago I joined the facebook page 'Magnesium Advocacy Group' very enlightening and surprising, especially about D3.....
This study was mentioned on the site
medscape.com/viewarticle/85... - entitled
Fibromyalgia Linked to Deficiencies in RBC Magnesium, IGF-1.
As far as I am aware, in UK RBC Mag tests are only available privately, although not that expensive....
I personally don't have Fibro, but know many who post here do.