Vitamin D deficiency is linked to BOTH fibro and anxiety. And I have to tell you, as simple as it may seem, it WORKS! I take 1000 mg a day and my anxiety is almost non existant now...I used to have it so bad that my thoughts were scary. I used to wake up in the night with panic thinking I'd left newborn grandaughter in the car, or other crazy things like that. I'd also check the car several times a day to make sure I hadn't. My anxiety is really strange...and I can't control it without Vitamin D. I refuse to take meds, they just cause other problems