I started having severe joint pain and chronic fatigue several months ago. The pain is so severe at times that I can barely walk or sleep. I have hard knots popping up on my forearms near my elbow, my hands, wrists, ankles, and feet. My doctor said my blood tests are all normal except for an extremely low vitamin D level. She said the vitamin deficiency is the cause but after weeks of taking 50,000 IU of vitamin D there is no change in the pain and stiffness of my joints. She doesn't have an explanation for the weird knots either. I'm desperate for relief. Could this be RA?