In my opinion, you do what you can within reason, then see what your labs say. The easier your regimen, the more likely you are to stick to it.
I don't take oral iron (except what's in the prenatal), so I don't worry about it. I take my vitamins twice a day, along with the rest of my pills, except for levoxyl, which I take out of my evening pill set and put on my nightstand next to my drink, so one of the times I wake up during the night, I take it, away from food and other pills.
I take my calcium, VitK and MgCit together twice a day, because they supposedly help each other get absorbed, and when I added the MgCit, my PTH number improved noticeably. Other than that, I haven't had any issues based on lab work.