Very true. That said, I've been taking 5000IU daily for the last couple years after a blood test showed my levels were a bit low. As of last week, my 25-Hydroxy

Very true. That said, I've been taking 5000IU daily for the last couple years after a blood test showed my levels were a bit low. As of last week, my 25-Hydroxy D level is 76, near the middle of the 30-100 normal range. Everyone's different: what's right for me isn't right for you. I just mean that to demonstrate that it's possible for some healthy adults to take a pretty significant amount every single day and have perfectly reasonable blood levels.