A very general approach to calculate the X-ray absorption spectra of non-magnetic as well as magnetic solids is presented. Describing the final states in the framework of spin-polarized relativistic multiple scattering theory (MST) allows us to account simultaneously for all relativistic effects and magnetic ordering and that way for magnetic dichroism. Using the full potential mode of MST, in addition, enhances the accuracy of the calculated absorption coefficient. Compared to a muffin-tin or an atomic sphere approximation construction of the electronic potential the full potential mode is expected to lead, in particular, in the XANES-regime and for relatively open structures to remarkable changes. Results for the L 2,3-edge of bcc-Fe are presented and discussed.