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Trace Elements

What Are They, Nutrition, and More

Author: Jessica Rivas

Editors: Ahaana Singh, Lisa Miklush, PhD, RN, CNS

Illustrator: Jillian Dunbar


What are trace elements?

Trace elements refer to any chemical element that is present in the human body in very small amounts, usually less than 0.1% by volume. Most trace elements can be classified as nutritionally essential, probably essential, or potentially toxic. 

What are trace elements in nutrition?

Nutritionally essential trace elements are required parts of an individual’s nutrition. These elements contribute to vital bodily functions, including metabolic function, tissue repair, growth, and development. Because the human body cannot naturally synthesize these elements, it is essential that people consume them through their diet or by using supplements. Excess consumption of these elements can have potentially toxic effects. Nutritionally essential trace elements include iron, copper, cobalt, zinc, selenium, chromium, iodine, and molybdenum. 

Iron plays an important role in transporting oxygen throughout the body through the blood. Iron deficiency can lead to anemia (deficiency of healthy red blood cells) and has also been linked to upper alimentary tract cancers. 

Copper, the third most abundant trace element in the human body, works with iron to form healthy red blood cells and is an essential component of many enzymes involved in chemical reactions throughout the body. It also plays an important role in maintaining the strength and health of blood vessels, nerves, and bones. 

Cobalt can be found in organic and inorganic forms. In the organic form it forms a vital part of vitamin B12 (AKA cobalamin) and contributes to the formation of amino acids and neurotransmitters. Conversely, inorganic forms of cobalt can be toxic to the human body. 

Zinc contributes to many functions in the body but is most importantly associated with cell division, cell growth, tissue repair, and metabolic function. It also aids the immune system in fighting off viruses and bacteria. 

Selenium plays an important metabolic role as an antioxidant (known to prevent or reduce damage caused by oxidation in the body). Chromium also contributes to metabolic function, as it plays a key role in regulating sugar, fat, and protein levels in the blood. 

Iodine is a very important element within the thyroid hormones thyroxine (T4) and triiodothyronine (T3). These hormones are essential in metabolism, growth, and development of the human body. 

Finally, molybdenum is required for a few enzymatic functions involved in digestion and excretion. 

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How many trace elements are there in the human body?

There are approximately 21 different types of trace elements in the human body. However, the exact number is unknown, and ongoing research continues to adapt this list. Each of the trace elements has different roles and functions within the body, and a deficiency or excess may lead to various clinical manifestations. 

In addition to the nutritionally essential trace elements, there are a variety of probably essential elements and potentially toxic elements. These classifications are largely based on suggestive and ongoing research. The probably essential elements include manganese, silicone, nickel, boron, and vanadium. 

Meanwhile, the potentially toxic elements include fluoride, lead, cadmium, mercury, arsenic, aluminium, lithium, and tin. 

What are the most important facts to know about trace elements?

Trace elements refer to any chemical element that is present in the body in very small amounts. Trace elements can be classified as nutritionally essential, probably essential, or potentially toxic. The nutritionally essential elements are required for proper physiological and metabolic functions. At least 21 trace elements have been described in the human body and each one has different functions. Deficiencies or excess of any of the trace elements can cause various clinical manifestations and affect one’s growth and development.

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Related links

Zinc deficiency
Iodine deficiency
Iron deficiency anemia
Arsenic poisoning
Lead poisoning

Resources for research and reference

Trace elements in human nutrition and health. (1996). In World Health Organization. Geneva: World Health Organization.

Mehri, A. (2020). Trace Elements in Human Nutrition (II) – An Update. International Journal of Preventive Medicine (11): 2. DOI: 10.4103/ijpvm.IJPVM_48_19

Bhattacharya, P. T., Misra, S. R., & Hussain, M. (2016). Nutritional Aspects of Essential Trace Elements in Oral Health and Disease: An Extensive Review. Scientifica, 2016. DOI: 10.1155/2016/5464373

Trace Elements. (1989). Diet and Health: Implications for Reducing Chronic Disease Risk. National Academies Press.