Nerve and muscle needs magnesium, calcium and D to function.  These are the workers of muscle and nerve. No minerals equates to poor nerve and muscle function. It is like hiring a staff of five to tend a party of 5000.  Not enough!! You should get your Vit D checked because it is a rampant deficiency we cope with because we are all indoors all the time.   I just discovered that I have a vitamin D deficiency and am so empowered to know that diet and sunshine alone can cure my muscle aches, weakness, depression, irritability and memory problems!! You too, can feel better if you incorporate vitamin D rich foods and at least 20 minutes in the sun daily. You have to do it though, taking a vitamin supplement will not be enough.  I learned the deficiency can lead to immunosuppressive conditions and auto immune disease which may be why you are dealing with a diagnosis of autoimmune disorders!!  Another issue relating to your digestion that can relat to Vit D deficiency, could be gluten intolerance, otherwise known as celiac disease; or Crohn's disease, which is related to Vitamin D deficiency.  If you tested negative for celiac, just try a gluten free diet and see if it helps, lab testing is not error proof. It is all interconnected.  Have you tried a gluten free diet?  I know how hard it is to change a diet. I am like a robot when it comes to food. I eat the same things over and over and complain about how bad I feel, but I have had it with the memory fog, and depression and am dedicated, and I mean life changing dedicated to changing my diet. Why do I allow myself to suffer??? I thought I had some horrible disease and all was hopeless, but it is just my diet, yeah! I am thrilled to know the reason the doctors cannot find something wrong is because I am healthy, but deficificient in Vit D. Research Vitamin D, and gluten free diet and do it, stick to it and get out in the sun, I hope you feel better. We all should be healthy and happy!!  Oh, oddly I live in the valley of the sun, Phoenix, and feel my worst in the summer, go figure? Be sure to incorporate dairy with each meal so that you can aborb Vit D.  Very important, and so much cheaper than searching endlessly for an illness or dealing with the long term effects of deficiency.  I pray you try this and it helps, give it some time. The most important thing is to get into the sun. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&ved=0CGkQFjAA&url=http%3A%2F%2Fods.od.nih.gov%2Ffactsheets%2FVitaminD-HealthProfessional%2F&ei=2HQHUPu1G4ak8ASWnPmbBA&usg=AFQjCNEt7zbgdoxW0Vkacc3QxZmtjvKdKw