“...supplements every day containing: vitamin D 50,000 mg—the daily requirement is 600 mg or 400 IU...”
The writer apparently didn’t check units of vitamin D at all. 1 microgram is 40 IU, so 50,000 milligrams would be two billion IU. 600 milligrams would be 24 million IU, not 400. Those are pretty high doses indeed.
I take 1000 IU’s per day.........................