How to avoid vitamin d overdose if i like lots of milk and sun?

Enjoy in moderation!: A dermatologist would likely advise you to avoid too much sunlight, to avoid skin damage and risk of skin cancer. It would be very difficult to drink enough milk to cause vitamin d overload, even if you were getting lots of sunlight. Your vitamin d level is likely to be nice and healthy!

Stop worrying: You can't get hypervitaminosis D from sunlight as there's not enough precursor in your skin and sunlight turns it off -- this self-regulates. There has never been a case of clinical vitamin D toxicity from diet. A couple of labs are labeling high vitamin D levels "toxic"; most of the pathology community thinks this is misguided. Glad you've got some good habits; sunscreen as needed.