My Dr. has prescribed over 3,000 units of vitamin D per day for me, and I've been taking it now for a couple of years, and I have not noticed any change in the way I feel. I've had fibro now for over 25 years, and it has affected every part of my life. Even so, adversity builds patience, character and empathy for others, and I hope I have grown to have at least a little of each.