Alterosa is a Brazilian municipality in the South of the state of Minas Gerais. According to latest data from IBGE, its population is estimate…Alterosa is a Brazilian municipality in the South of the state of Minas Gerais. According to latest data from IBGE, its population is estimated to be 14,517. The inhabitants of the city usually travel to the nearest city, Alfenas, when they are in need of more sophisticated supplies.