Calculations are made for the electron capture and loss cross sections and the charge state distributions of uranium ions at energies of 200 MeV/nucleon, 437 MeV/nucleon and 962 MeV/nucleon colliding with low-Z and high-Z targets. The charge states of the projectile ions are determined from the equilibrium condition between electron loss from the ion and electron capture from a target atom into the projectile ion. The electron loss cross sections are formulated using the relativistic Born approximation. The electron capture process is considered to be non-radiative electron capture and radiative electron capture in the relativistic impact velocity range.