[trevorkoob]

Other than the value you are aiming for (I personally aim for the upper edge of the normal range), I agree with the immense variability in dosage, and also would like to mention imprecision in vitamin D bloodwork tests as well.

Thankfully throughout my Vitamin D research, I found low risk of overdose, and cases of immense accidental overdose that appear to have been treated successfully (mainly by stopping the over-intake).