Comment about the letter entitled 'Scalar fields as dark matter in spiral galaxies'

The objective of this brief comment is to point out several problems associ ated with the general framework underpinning the letter `Scalar fields as d ark matter in spiral galaxies' (Matos T and Guzman S 2000 Class. Quantum Gr aze 17 L9) and with its application in this work in particular. Concretely we will focus on three points, namely, the singularity of the scalar field configuration, the analysis of the geodesics and the way in which the autho rs `add' velocities in trying to account for the effects of the luminous ma ss on the motion of the test particles.