  The Lorentz invariant formalism for description of neutrino flavor
oscillation in moving and polarized matter is developed. It is shown that the
neutrino effective potential, which determines the effective mass difference
between neutrinos in matter can be sufficiently changed by relativistic motion
of matter. In the case of matter motion parallel to neutrino propagation,
matter effects in neutrino flavor oscillations are suppressed. In the case of
relativistic motion of matter in the opposite direction sufficient increase of
effects of matter in neutrino oscillations is predicted. The dependence of the
matter term in neutrino effective potential on the values and correlations of
the three vectors, the neutrino and matter speeds and matter polarization, is
discussed in details.
