The goal of calculating the one loop hadronic contribution to the muon
anomalous magnetic moment using lattice QCD, with an error under 1%,
requires the calculation of the disconnected contributions. We discuss
some of the numerical challenges of computing disconnected vector
correlators, in lattice QCD calculations using the highly improved
staggered quark (HISQ) action. We report preliminary results and
compare them to the results from other lattice QCD calculations.