A general term for dietary essential nutrients required in relatively small amounts (less than 50 milligrams per day). For example, micronutrients include vitamins (organic compounds) and trace elements (e.g., Fe, Cu, Zn, I, Se, Mn, Mo, Cr, F, Co) for human consumption that may be potentially provided by ingestion of clays, whereas clays in soils provide these nutrients for plants.
Cf., macronutrient