Ability to enforce and/or check player profile fields for completeness retroactively

When we first setup our club, we did not require birthdates on player profiles. Now we require them, but there is no way to retroactively enforce that this data be provided for existing players - only future players. I would like the ability to enforce players to have completed profiles in order to sign-in, i.e., upon login, or upon registering, signing up for things, etc. pre-validate the profile for completeness. I might even add that this be extended to require members to do a periodic validation of their profiles for correctness, as often times people change addresses, etc. and that information isn't guaranteed to be current without such a mechanism in place.