I was diagnosed with fibromyalgia & then osteoarthritiis & osteoporosis going back to 1997 (by several doctors). I took Hydrocodone for three and a half years (10-mg 3 times a day) and was confined to a wheelchair until one day a 'retail clerk' on the phone suggested I try low dose magnesium supplements (250-mg a day). In a week I felt better, in 10 days I felt like a new person. 2 months later I (very painfully) got off the Hydrocodon, and am now (a year later) walking comfortably and am pain free. A recent study of over 9000 people over a 10 year period could find no evidence that calcium supplements were of any benefit. Ah, but magnesium WAS. By the way, a blood test for magnesium is not a marker for a bone deficiency ...... Why don't doctors know this ?