From Soil to Table: A Comprehensive Review of Selenium-Fortified Foods.

Selenium, an essential trace element with a narrow nutritional window, plays critical roles in human health primarily through selenoproteins. Its dual nature, being vital yet potentially toxic, underscores the importance of precise intake. Geographical disparities in soil Se content lead to widespread dietary deficiencies, driving the advancement of Se-fortified foods. Food selenium fortification strategies are implemented through modern techniques, including selenium application to soil or foliage, crop genetic engineering, microorganism-mediated transformation, and direct supplementation of animal feed or processed foods. Selenium compounds ingested through selenium-fortified foods are typically categorized into inorganic and organic types. Organic (e.g., selenoamino acid) and inorganic (e.g., selenate) selenium are absorbed and transformed through amino acid transport pathways and ion transport pathways, respectively, and this distinction leads to differences in their metabolism and toxicity. Excessive selenium is toxic and characterized by nerve damage, hair/nail loss, and gastrointestinal complaints, which can lead to death in severe cases. Organic forms exhibit superior bioavailability, higher nutritional value, and lower toxicological risks. This review comprehensively examines the preparation methods, commonvarities, and the impacts of selenium fortification on these foods. The conversion of various primary dietary selenium compounds in the human body is compared, and the impact of dietary selenium supplementation on human health is evaluated. Additionally, the recommended selenium intake ranges for different age groups specified by various countries and regions are highlighted, with the aim of guiding individuals to scientifically supplement selenium.