Trapping of ion-irradiation induced defects has been studied in Na-implanted polycrystalline Fe, Ni, and Mo. The samples were implanted at room temperature with 250-keV23Na+ions to a fluence of 1.5 × 1017cm−2. The Na concentration distributions were characterized using nuclear reaction via the resonant reaction23Na(p, σ)24Mg. The trapping and detrapping of Na-implantation and proton-irradiation induced defects were observed via their decoration with hydrogen. The H distributions were measured with the nuclear resonance reaction1H(15N, ασ)12C. The formation of defect-hydrogen complexes is interpreted by vacancy migration to Na followed by trapping of H from the bulk. To elucidate the mechanisms, the Na-doped samples were also post-irradiated with 100-keV protons and 6.4-MeV15N2+ions, and isochronally annealed at 300-970 K.