We investigate the thermodynamics of the flavour sector of the Sakai-Sugimoto
model in the presence of a magnetic field. Renormalizing the euclidean
Dirac-Born-Infeld action in the antipodal limit, we find for the confined and
deconfined phases positive contributions to the pressures that grow with the
magnetic field. We also obtain positive magnetic susceptibilities indicating a
paramagnetic behaviour of quarks. Using these results we estimate a
\lambda^2/N_c correction to the deconfinement temperature that decreases as a
function of the magnetic field.Comment: V4 1+20 pages, 6 figures, references and one figure added. Version
published in JHE