Selenium from dietary sources and motor functions in the Brazilian Amazon

► We evaluated the influence of Se on psychomotor functions, taking into account exposure to Hg and Pb. ► Elevated plasma Se is associated to better motor performances. ► Associations between Se and motor performance are stronger when taking Hg exposure into account. ► For this population with elevated Hg, high dietary Se may be critical for brain and muscle functions. ► These findings may not be applicable to populations with lower Hg and/or Se status.