Trying to reduce bottles of formula.

Hi everyone! As my son is now 11 months and 2 days, I'm trying to reduce formula bottles. He does not want one during the night anymore and does not seem fussed in the morning whether he has one or not so thinking of dropping that one. He has a bottle at 12pm (for his nap) and at 7 ish for bedtime as he still feeds to sleep.. as daily intake would be around 400ml I need to introduce a multivitamin. Which one do you use? Thank you!