According to what I have ran across online they say even doses up to 10,000 units is still safe. Since I don't see me going out riding in shorts and a tank anytime soon (ice storm on the way, puke!) I guess I'm stuck taking D3 supplements and hoping for the best. I admit I don't get outside nearly as much as I once did and when I do I'm completely covered aside of my face. I have to do alot more workouts in the gym these days.