  We consider chiral loop corrections to the effective couplings which describe
the strong interactions of two heavy mesons of even or odd parities and a light
pseudoscalar meson, within a framework which combines heavy quark effective
theory and chiral perturbation theory. The strong couplings are extracted from
the experimental results for the decay widths, after including chiral
corrections. We find that the introduction of positive parity heavy meson
fields into the framework gives relevant contributions to the chiral loop
corrections of the effective couplings. The counterterms' contributions are
studied by making a randomized fit distribution of the relevant couplings at mu
= 1 GeV. Then we discuss the chiral extrapolation based on calculated loop
contributions. The inclusion of positive parity mesons in the chiral loops is
found to be important for the lattice QCD studies of charm meson properties,
where the knowledge of chiral limit behavior is required.
