Abstract
BACKGROUND: Micronutrient inadequacies are estimated to affect billions of people worldwide, yet these estimates exclude fortification. There are no global estimates of the impact of current fortification programmes on micronutrient inadequacies. We aimed to estimate how improving existing programmes or establishing new ones affects the prevalence of micronutrient inadequacies and to estimate their global costs. METHODS: In this modelling study, we estimated the prevalence of inadequate intakes of 13 micronutrients across 185 countries by integrating global modelled dietary intake data from the Global Dietary Database, with fortification programme parameters from the Global Fortification Data Exchange. We modelled six scenarios: no fortification, current fortification, improved compliance, aligned standards, aligned standards with improved compliance, and aligned standards with improved compliance and expanded coverage. Implementation costs were calculated as the sum of premix, industry-related, and government costs across five fortified foods: wheat flour, maize flour, oil, rice, and salt. FINDINGS: Compared with no fortification, current fortification programmes prevent 7·0 billion inadequate person-nutrient intakes annually at a global cost of $1·06 billion (mean of $0·18 [SD 0·28] per person, 2021 US$, across the five fortified foods), with iodine fortification alone preventing 3·3 billion inadequacies. Despite current fortification, 38·6 billion inadequate intakes persist. Improving compliance would prevent 13·1 billion inadequacies at a global cost of $3·48 billion annually (mean $0·23 [SD 0·33] per person). Aligning standards and improving compliance would prevent 17·2 billion inadequacies at $6·56 billion annually (mean $0·63 [SD 0·53] per person). Aligning standards, improving compliance, and expanding coverage would prevent 24·7 billion inadequacies at $9·19 billion annually (mean $1·15 [SD 0·58] per person), although 20·9 billion inadequacies would remain. INTERPRETATION: Fortification is a cost-effective intervention that greatly reduces micronutrient inadequacies, particularly for iodine and iron. Improving compliance offers immediate gains. Aligning with international guidelines and expanding programmes could triple their effects but cannot eliminate all inadequacies, underscoring the importance of complementary approaches to improve diet quality. FUNDING: Swiss Agency for Development and Cooperation and the Gates Foundation.