  Extended Higgs sectors have been studied extensively in context of dark
matter phenomenology in tandem with other aspects. In this study, we compute
radiative corrections to the dark matter-Higgs portal coupling, which is in
fact a common feature of all scalar dark matter models irrespective of the
hypercharge of the multiplet from which the dark matter candidate emerges. We
select the popular inert doublet model (IDM) as a prototype in order to
demonstrate the impact of the next-to-leading order corrections, thereby
probing the plausibility of extending the allowed parameter space through
quantum effects. Given that the tree level portal coupling is a \emph{prima
facie} free parameter, the percentage change from loop effects can be large.
This modifies the dark matter phenomenology at a quantitative level. It also
encourages one to include loop corrections to all other interactions that are
deemed relevant in this context.
