Soil Micronutrients, Food Systems, and Human Health at Regional Scale

AbstractHidden hunger is the deficit of minerals and vitamins in human food. The minerals including micronutrients partly originate from soils, and their supply in food systems strongly depends on their concentration and availability in soils. We revised the existing literature to reproduce the chain of 10 major microelements (B, Co, Cr, Cu, Fe, I, Mn, Mo, Se, and Zn) from parent rocks to soils, from soils to plants, from plants to animal meat, and finally from crops and meat to human body. Mechanisms of microelements’ transport from one medium to another were discussed with an emphasis of pedogenetic processes, which might lead to concentration or diffusion of elements in comparison with the parent rock. We proposed an approach based on hypothetical concentration of microelements in food depending on dominant parent rocks and soils in particular areas, and tested it for four elements (Cu, Fe, Mn, and Zn) in three regions: Sichuan province in China, Republic of Uzbekistan, and Central-Northern region of Mexico, taking into account the dietary peculiarities in each region. We considered food consumption by rural population because it was more dependent on local agricultural products. The region with the lowest concentration of micronutrients in dairy ration was the Sichuan province, where Cu, Fe, and Zn were present in food in the quantities less than the required daily dose. In Central Mexico the daily amount of Cu in food was in the recommended range, and other elements above this range. In Uzbekistan all the four elements were potentially present in food in amounts higher than the recommended amounts. Current study did not consider bioavailability of micronutrients in food, and thus their amount might be overestimated.