If i remember correctly, i took my multi and one of my calciums in the morning with a tbsp of greek yogurt (if i didn't i'd get nauseous because i don't eat in the mornings...never did, even pre-surgery, and still don't). then 2 more calciums with Vit Ds later in the day/evening.
i only had to take iron for 1 week, and during that time i didn't take the calcium cuz they were sooooo humongous and i didn't yet learn the greek yogurt trick.
i remember sometime around month 2 post op i started taking those chewable calciums (chocolate flavoured, yum!). did this for a couple months then went back to the ginormous horse tablets.
now i am in no way endorsing the following (without talking to your doc first), but full disclosure, i stopped taking any/all vitamins/supplements around the 1.5 year mark. my doc/team knew this and had no concerns because my labs always came back satisfactorily....and continued to do so until my last followup with my surgeon at the 5 year mark last fall. going forward i suppose this will need to be monitored at my annuals with my primary care doc.
oh, i should mention i'm also a sleeve....