This guideline provides global, evidence-informed recommendations on the use of indicators for assessing a population’s iron status and application of the use of ferritin concentrations for monitoring and evaluating iron interventions. his guideline aims to help WHO Member States and their partners to make evidence-informed decisions on the appropriate actions in their efforts to achieve the Sustainable Development Goals, and the global targets as put forward in the Comprehensive implementation plan on maternal, infant and young child nutrition and the Global strategy for women’s, children’s and adolescents’ health (2016–2030).