Hello,   I was searching on internet to find out what is happening to me and finally came across your web site.   I have many similar symptoms you and other people. My story starts 2 months ago, in July 2010. It started with kind of dizziness ( I describe it as "kind of " because it was completley something different), strange headaches, speaking and concantration difficulties(brain fog), extrem tiredness and need to sleep (slept 13 hours without any waking), pain in the back of my eyes, kind of pain on my throat, muscle weakness, teeth grinding(or tight jaw) and burning and dry eyes. I went to doctor and I had my blood tested. Doctor said that I am a vitamin D deficient. I've started using pills combination of Calcium and Vitamin D3 (as vitamin D deficiency causes osteoporosis). I am taking 2 tablets every day and each contains 400IU Vitamin D3. I felt much better and there were no any symptoms until last week, when my pills were running out, I decided to take once a day until I got my prescription. I can say that I used 1 pill a day for 5 days and symptoms are back. It's been 5 days I've been taking the regular dose again but symptoms are not dissapearing. If they will dissapear for a long time I want to try not to use them for few days to see If the cause of my symptoms are because of Vitamin D deficiency.   On my pills bottle it is written that side effect of excessive calcium level in your blood can cause weak muscles and dizzness as well. So, I am not sure if my calcium level got higher because of those pills.   My symptoms are very similar to MS symptoms and I feel like I am likely to have it (relapsing remitting MS). My vitamin deficiency is caused by lack of sun light because I used to live in Turkey and now living in London. I have been here for 3.5 years and even during the summer there is a short period when you can absorb proper sunlight. I was a very healty and active person and I am relatively young 31 years old. I remember how hard I worked and got tired and came home did excercise, cooked, washed the dishes etc. ayear ago but now with these symptoms it is eveb very hard to move my arm or speak. Brain fog and speaking difficulty are worse than tiredness. I have been studying for a year, doing MSc and these symptoms appread during my research project, fortunately I managed to do it. There is just one thing left is my presentation. I hope my symtpoms will dissapear in two days and I can give my presentation.   At the beginning I tought the symptoms were because of the high stress level of my life, school, job, wife, family everything, loads of pressure but it appeared that it could be because of MS or anything else. I asked my doctor if I could have MRI but she said she should treat the vitamin D deficiency and see if the cause is lack of Vitamin D. I will use those pills 4 months more and see my doctor again.   I hope all of us will find a solution to make our life better than it is now.