I personally aim for 10,000 IU D3 daily from either sun or supplement. In normal times, living in New York, I would supplement 10,000 IU D3 from November through March, and then I would make sure to be outside 1 hour a day with at least arms and face exposed.

Shots of 250,000 IU are given clinically and the therapeutic dose was traditionally 50,000 IU D2 weekly - corresponding to a dose of about 3,500 IU D3 daily.

I highly recommend getting tested for kidney disease if you are worried and get multiple vitamin D tests - the tests are imprecise but will give you a general idea of what your levels are.

No, it won’t, but that’s only after a certain limit that’s much higher than 5000IU. Even if you spend all day in the sun, your body will stop the synthesis at a certain level (10000IU in the day is what I had read long ago, but that may be incorrect or outdated).

In other words, 5000IU is much lower than what the body would naturally produce when exposed to sunlight for long durations in a day (assuming good latitude, sunny season, lower atmospheric pollution, around noon, lighter skin tone, etc.).