It would probably be wise to not post your opinion on things like vitamin dosages unless you're a medical doctor.
My doctor prescribed 1 week of 15000 IU a day, then a week of 10000 IU, then a running dose of 5000 IU a day. I've seen measurements of 50k IU from a day in the sun. 3000-5000 is not too much or "obscenely high" for many people, but as with literally everything like this, its best to consult a doctor about an individual's needs.