I have been dxed with low vitamin d (25 ng/ml) and have just begun taking 5000 iu/day. My calcium levels were normal (9.6), but I have symptoms identical to low calcium – muscle twitches, spasms, (twitches worst in quads and around the mouth), parasthesias (mostly fingers and around mouth), tightness in throat, extreme fatigue, and more. These symptoms are severe and the fatigue is debilitating. I've had some of these symptoms on-off over the past couple years, but brushed them off to my low thryoid. I had recent stress that seemed to push me over an edge and everything intensified and has become steady, which is why doc found the d deficiency. Exertion worsens it all. Is it possible to have calcium dysregulation with low vitamin D that can cause such severe symptoms and shows normal blood calcium levels (and with a vitamin D that doesn't seem all that low)?