To be frank, I have not done a lot of reading on this in a long time, but my overall impression is that multi-vitamins don't really have enough of anything to make a difference unless you are critically deficient in something. So they don't really provide enough of anything to be contra-indicated for most people either.
So I personally prefer to limit vitamin and mineral supplementation to specific things that I feel I need to boost. Generally for me that's C and D, although I'm planning to have a close look at magnesium and K2 for heart health.
I'm T2, and I'm completely ignorant on T1 health issues. As I don't know which type you are, I'd say take my opinion for what it's worth.