  We calculate vacuum polarization corrections to the binding energies in
neutral alkali atoms Na through to the superheavy element E119. We employ the
relativistic Hartree-Fock method to demonstrate the importance of relaxation of
the electronic core and the correlation potential method to study the effects
of second and higher orders of perturbation theory. These many-body effects are
sizeable for all orbitals, though particularly important for orbitals with
angular momentum quantum number l>0. The orders of magnitude enhancement for d
waves produces shifts that, for Rb and the heavier elements, are larger than
those for p waves and only an order of magnitude smaller than the s-wave
shifts. The many-body enhancement mechanisms that operate for vacuum
polarization apply also to the larger self-energy corrections.
