For the first time, a nonlocal pseudopotential of electron-ion interaction for metallic helium is proposed and calculated from the first principles. With the help of this pseudopotential in a wide range of densities, the pairwise effective interionic interaction in metallic helium in the case of singly ionized helium atoms is calculated. At the same time, no fitting parameters, which are the characteristic of the theory of pseudopotentials in metal physics, are used. The results of these calculations are compared with the results of calculations of pairwise effective interionic interactions for doubly ionized helium atoms and metallic hydrogen. It is concluded about the possibility of the existence of metallic helium in a stable state at relatively low temperatures and a wide range of densities. Such conclusions are fundamentally related to the effect of orthogonalization of the wave functions of the conduction electrons and the wave functions of the internal electrons of helium ions, which is taken into account when constructing the pseudopotential.