At levels above 10,000 IU per day you should take precautions to prevent calcification of the soft tissues: Take Vitamin K (100-200ug), Boron (10-20mg) to prevent calcification. Vitamin A should be dosaged at a ration 1:1 - 1:4 compared to Vit D (same amount or 4 times more of vitamin A) because A and D are anthagonists.
Below 10,000 IU there's only benefits of better health and no risk or precautions needed.