Thank you for the question.
We've included it because we've cooperated with a copacker that worked with a different vitamin & mineral mix than we've come to use. It's similar in most respects, but is different in (still) including sodium flouride and doesn't have a vegan source of vitamin D.
A while ago we wrote a piece about flouride which is based on the following EFSA recommendation:
We don't believe that flouride has negative side-effects at the levels in our products and that in general it's something good (but also already available in for instance tooth-paste).