  We study the magnetic catalysis of chiral symmetry breaking in the ABJM
Chern-Simons matter theory with unquenched flavors in the Veneziano limit. We
consider a magnetized D6-brane probe in the background of a flavored black hole
which includes the backreaction of massless smeared flavors in the ABJM
geometry. We find a holographic realization for the running of the quark mass
due to the dynamical flavors. We compute several thermodynamic quantities of
the brane probe and analyze the effects of the dynamical quarks on the
fundamental condensate and on the phase diagram of the model. The dynamical
flavors have an interesting effect on the magnetic catalysis. At zero
temperature and fixed magnetic field, the magnetic catalysis is suppressed for
small bare quark masses whereas it is enhanced for large values of the mass.
When the temperature is non-zero there is a critical magnetic field, above
which the magnetic catalysis takes place. This critical magnetic field
decreases with the number of flavors, which we interpret as an enhancement of
the catalysis.
