The largest dosage of D3 I can find on Amazon is 5000 IU in a 240 capsule bottle. To take 60000 IU, you'd have to take a dozen capsules daily, getting a new bottle every 20 days, probably multiple times.
While possible, it does seem unlikely.
While possible, it does seem unlikely.
I'm curious why an acute high dose would be preferable over a lower dose taken daily.
It's not quite an acute high dose. The body produces the equivalent of 10,000 IU per day in high sun exposure, so 60K per week tries to achieve that level. I believe the high dosage is simply convenience. The 2K IU daily dose is pretty common as well.
Taking 100000 IU per day for months/years is not necessarily toxic, especially when reducing calcium intake.