I'm 5" 11" 225 pounds and I take 25,000mg Vitamin D daily for the past 6-months. 25,000 brings my blood level to 80ng/ml. The more body fat you have the more vitamin D you need to increase your blood-level. I was taking 50,000iu's daily which brought my blood levels up to 130ng/ml. I read a book that I bought on Amazon about mega-dosing vitamin D. The only thing I can say is that I didn't get sick one time this past winter. I'm going to stay on the 25,000iu's because there is a lot of research that says vitamin D is beneficial. I just started Iodine 2-weeks ago. Hard detox now up to 200mg daily.