I have a question that no one so far has been able to answer. I have asked my doctor, store nutritionist and a naturopathic doctor that I have used, no answer or solution, so I come here to the Vitamin D experts! OK, I have an autoimmune disease, doctors have not decided which one, still working on it. Anyway, I used to take D3 before I got sick, up to 5, 000 units daily of D3 without any issues. After I got sick I started having problems when I took them, would get additional inflammation in my hands and knees, so I stopped. Recently my blood test came back with levels under 10, so I tried taking D3 again to bring them up, but every time I do I get severe fatigue the next day when I get up from sleeping. I can barely get out of bed! After a while I am OK again, but it is causing some problem. My question is what is happening and how can I correct it. Hope someone can help me. Thank you.