Micronutrient deficiencies affect more than two billion people worldwide, particularly in low‑ and middle‑income countries (LMICs), where dietary quality is limited by low consumption of nutrient‑dense foods. Biofortification—enhancing the vitamin and mineral content of staple crops through conventional breeding, agronomic practices, or genetic engineering—offers a cost‑effective and sustainable strategy to address this “hidden hunger.” This paper synthesizes nearly two decades of evidence from the HarvestPlus program and partner institutions on the development, bioavailability, efficacy, and large‑scale dissemination of biofortified crops. Controlled feeding trials consistently demonstrate that biofortified varieties of beans, pearl millet, rice, maize, cassava, and sweet potato provide significantly more absorbable iron, zinc, and provitamin A than conventional counterparts, improving micronutrient status and, in some cases, cognitive and physical performance. More than 340 biofortified varieties have been released across 40 countries, with more than 15 million farming households growing them. Delivery models and demand‑creation strategies—especially for visible traits such as provitamin A carotenoids—have shown high consumer acceptance. Cost‑effectiveness analyses indicate that biofortification often delivers greater health impact per dollar than many standard nutrition interventions. The paper also evaluates future scientific opportunities, including improved biomarkers, enhanced bioavailability traits, and the role of transgenic and genome‑editing technologies in advancing multi‑nutrient biofortification. Integrating biofortification into national policies, seed systems, and food value chains is essential for achieving resilient, nutrition‑smart food systems capable of improving diets sustainably, particularly in the context of climate change and global health disruptions such as COVID‑19.