Eating within planetary boundaries - a cross-country analysis of iodine provision from the EAT-Lancet diet

The EAT-Lancet Commission's 2019 reference diet promotes health and environmental sustainability through predominantly plant-based foods, raising concerns about micronutrient adequacy, particularly iodine. This study evaluated the iodine content of the EAT-Lancet diet across sixteen countries using national food composition data. Iodine intake was modelled under three scenarios: (1) strict adherence to specified food items; (2) inclusion of a broader range of foods within each group; and (3) a vegan adaptation. In Scenario 1, dairy products, fish, and eggs were primary iodine sources, with intakes ranging from 42 µg/day (New Zealand) to 129 µg/day (United Kingdom), covering 28-85% of the adult requirements. Scenarios 2 and 3 showed higher iodine levels in countries using fortified bread, but most remained below adult and pregnancy requirements. These findings underscore the need to carefully evaluate iodine provision of plant-based dietary recommendations, particularly in countries without a fortification policy, to prevent iodine insufficiency.