Finished 50,000iu Vitamin D3, 3x per week, now feel horrible again. My doctor put me on a prescription of Vitamin D3 50,000iu three times a week for three months. I felt the best I did in five years. I was struggling with weight gain, and being tired before the prescription for five years. I went off it the prescription in 5/2010, was re-tested .... "/>Weekly-d vitamin d3 50000 iu