Trace metals are the

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

s subset of

trace element __NOTOC__ A trace element, also called minor element, is a chemical element whose concentration (or other measure of amount) is very low (a "trace amount"). They are classified into two groups: essential and non-essential. Essential trace elements ...

s; that is, metals normally present in small but measurable amounts in

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

and

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

cells and tissues and that are a necessary part of

nutrition Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficient ...

and

physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

. Many biometals are trace metals. Ingestion of, or exposure to, excessive quantities can be

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

. However, insufficient plasma or tissue levels of certain trace metals can cause

pathology Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in ...

, as is the case with iron. Trace metals within the human body include

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

, chromium,

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...

cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...

, vanadium, molybdenum,

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

and others. Trace metals are metals needed by living organisms to function properly and are depleted through the expenditure of energy by various metabolic processes of living organisms. They are replenished in animals through diet as well as environmental exposure, and in plants through the uptake of nutrients from the soil in which the plant grows. Human

vitamin A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrie ...

pills and plant

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

s can be a source of trace metals. Trace metals are sometimes referred to as trace elements, although the latter includes minerals and is a broader category. See also Dietary mineral. Trace elements are required by the body for specific functions. Things such as vitamins, sports drinks, fresh fruits and vegetables are sources. Taken in excessive amounts, trace elements can cause problems. For example, fluorine is required for the formation of bones and enamel on teeth. However, when taken in an excessive amount can cause a disease called "Fluorosis', in which bone deformations and yellowing of teeth are seen. Fluorine can occur naturally in some areas in ground water. Trace metals include iron that can help to prevent anemia, and zinc that is a cofactor in over 100 enzyme reactions.

References

{{Reflist Biochemistry Nutrition Physiology Metals Analytical chemistry Geochemistry