Vitamins and supplements interacting

After months of trying all sorts of meds to manage my ADHD (PI), I have finally stuck with the same one for quite a while (generic vyvanse), and am starting to play around with my vitamins and supplements. HOLY COW I did not realize how heavily they were interacting. I stopped taking my multivitamin in the morning two weeks when I found out that vitamin C can lower absorption, and wow - huge difference. I didn't realize just how much more my meds could hit. I am messing around with magnesium in the morning, as I had heard that it can increase the absorbency of stimulants. I'm only on day three of that experiment, but so far, I think I'm noticing a difference. As a total science nerd, I like experimenting with this stuff - and it also makes me feel better to know that I can do other things before having to just up my dose again when my meds aren't hitting as they should be. Do y'all have any little vitamin or supplement hacks? I want to try them all and see what my perfect cocktail is :)