Molybdenum is used as plasma-facing material in tokamaks and as material for plasma optical diagnostic mirrors. Harsh conditions of neutron irradiation, exposure to hydrogen isotopes and helium, and high temperature result in degradation of molybdenum surface and ultimately limit the lifetime of fusion power plant. In the current paper, we investigate intake and subsequent thermal release of deuterium form self-irradiated by high energy (1 MeV) ions molybdenum as a function of irradiation dose. Several characteristic temperature regions where deuterium release takes place are identified and attributed to trapping of deuterium in intrinsic and radiation-induced microstructure defects. This attribution is further validated by molecular dynamics modelling which confirm that increase of deuterium as found experimentally is proportional to the increase of vacancy concentration found in simulations. Vacancy content saturates at damage level of around 0.2 dpa (displacement per atom), similar to recent modelling and experimental studies of iron and tungsten. Reflectivity measurements of irradiated molybdenum show that it is only slightly affected by damage up to 1 dpa.