As I am completely bedridden - and have been for a little over two years - I am seriously concerned about my bone density. Other than eating well and taking a vitamin D supplement, I do shift about in bed quite a lot - sometimes sitting up for periods or bending my knees up to try and put weight through my legs. I also have to move once a day onto the commode by the side of my bed, which will necessarily change how the weight is distributed through my body. Am I likely to be at serious risk of osteoporosis? I am a man, age 26, which I hope will work in my favour. In my previous life I loved to ski and throw myself down mountain bike trails, but I am seriously concerned that I will be prohibited from doing that in a hypothetical future when I no longer have ME because my bones will be too weak. I have also come across conflicting information regarding regaining lost bone density. Some sources suggest you can reverse bone loss to an extent, whereas others say that once it is gone it is gone. Does anyone have any insight into this?