> No, that’s literally what I was doing when I reached the excessive range:

That doesn't make it easy for most people. In my case it was barely enough to move the needle, but that's not how it will be for most people either.

> you can’t overdose on 5000 IU/day is wrong

Of course you can (though it would usually have to be really prolonged to actually cause you troubles, and even then it's mostly due to calcium rather than vit D itself). The vast majority of people won't, but you don't know whether you're in that group or not until you test yourself.

> Literally what I did.

That's good, but my post obviously used plural "you" as a general advice.

(BTW. There's no evidence of toxicity below blood level of 150 ng/ml, but there are many guidelines that consider levels way below that, such as 50 ng/ml, as "too high" already)