I'd fully recommend dropping down to 1-2,000IU after a course of these. But by all means these are great boosters, and over the winter months these will be invaluable to you. I would ask a doctor/GP before taking these long-term, and for them to test your vitamin d levels. I absolutely do not recommend you take 8,000IU daily like it suggests on the packaging unless you are certain that you need to do so as advised by GP.