In deuterated molecules such as [1-C-13]pyruvate-d(3), the nuclear spin polarization of C-13 nuclei can be enhanced by combining Hartmann-Hahn cross-polarization (CP) at low temperatures (1.2 K) with dissolution dynamic nuclear polarization (D-DNP). The polarization is transferred from remote solvent protons to the C-13 spins of interest. This allows one not only to slightly reduce build-up times but also to increase polarization levels and extend the lifetimes T-1(C-13) of the enhanced C-13 polarization during and after transfer from the polarizer to the NMR or MRI system. This extends time scales over which metabolic processes and chemical reactions can be monitored.