The human body consists of 60 different elements, including oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, and 49 other trace elements.
The human body is a complex work of art, made up of an immense number of atoms, precisely 7×1027 atoms. However, not all atoms are the same. Among the 118 known elements, 94 occur in nature, and the human body contains these 60 natural elements.
Based on the number of atoms and their contribution to the total weight of the human body, elements can be divided into three groups: major elements, minor elements, and trace elements.
The human body consists of 60 different elements.
The major elements, as the name suggests, are vital for human life and are the most abundant, followed closely by the minor elements. However, not all trace elements participate in the activities of the human body.
Major Elements
The four major elements in the human body are oxygen, hydrogen, carbon, and nitrogen.
About 60% of the human body is covered by water. Therefore, it’s no surprise that oxygen and hydrogen, the two elements that make up water, are among the most abundant in the human body. Oxygen ranks first, while hydrogen comes in third on the list.
Water (H2O) consists of two hydrogen atoms and one oxygen atom. Thus, hydrogen has a larger atomic percentage than oxygen and every other element in the human body. However, since oxygen is the heavier element (with an atomic weight of 16.00 amu or 2.6 x 10-23 grams), it contributes most to the overall weight of a person.
For an average person weighing about 70 kg, oxygen alone contributes 43 kg (65% of total body weight), while hydrogen accounts for 7 kg (10% of total body weight). In terms of atomic count, hydrogen leads all elements with a total atomic percentage of 62%, followed by oxygen at 24%.
Oxygen is also a component of all four organic compounds found in the human body.
Oxygen in the form of water helps regulate body temperature and osmotic pressure, while molecular oxygen (which we breathe in) plays a crucial role in converting glucose into ATP molecules. Oxygen is also a component of all four organic compounds (proteins, carbohydrates, lipids, and nucleic acids) present in the human body; however, too much oxygen can also be harmful. Like oxygen, hydrogen primarily exists in water and is found in all organic compounds.
Carbon, the essential element of organic compounds, is the second most abundant element in the human body, contributing about 18% of total body weight. Carbon is a fundamental element for all life on Earth and is the basic element of all organic compounds.
Following carbon in abundance is nitrogen, which makes up 3% of the total body weight. Nitrogen is the most abundant element in Earth’s atmosphere and enters our bodies along with oxygen with each breath. However, the human body does not use nitrogen in its gaseous form and thus expels it immediately. We obtain nitrogen from food. This element is a key component of amino acids (used to build proteins) and nucleic acids like DNA and RNA (genetic material).
Minor Elements
The minor elements include: calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium.
The human skeleton is primarily composed of calcium. Calcium is the fifth most abundant element and the most plentiful mineral in the human body, accounting for about 1.5% of total body weight. Ninety-nine percent is found in bones and teeth (in compounds like hydroxyapatite), and this element also plays an important role in muscle contraction and protein regulation.
Following calcium is phosphorus (1% of total body weight). It is primarily found in ATP (triphosphate) molecules and in bones, along with calcium.
Calcium and phosphorus, along with the four major elements, account for about 99% of the mass of the human body. (Photo: Zhaocarol/Wikimedia Commons).
Next on the list are potassium (0.35% of body weight) and sodium (0.15% of body weight). Their positively charged ions help transmit nerve signals and regulate fluid levels in the human body. Potassium also plays a role in helping the heart maintain a steady rhythm.
Sulfur (0.25% of body weight) is a component of several amino acids, such as cysteine and methionine, as well as vitamin H or B7 (Biotin) and vitamin B1 (Thiamine).
The last two elements that significantly contribute to the overall mass of the human body are chlorine (0.15% of body weight) and magnesium (0.005% of body weight). Chlorine is present in the stomach as hydrochloric acid, helping the body maintain water and salt balance, and acts as a catalyst in converting ATP to ADP. On the other hand, magnesium is involved in many metabolic processes and enzymatic reactions, while also serving a structural role in bones and teeth.
Trace Elements
There are 49 other elements found in trace amounts in the human body. However, among these 49 elements, only a few are considered essential for human life, while some others are harmless but not beneficial. These substances are regarded as impurities, such as aluminum, titanium, cesium, silver, etc.
The trace elements necessary for human life include: iron, zinc, copper, iodine, selenium, chromium, manganese, lithium, molybdenum, and cobalt. Iron is likely the most important, as it is responsible for transporting oxygen to red blood cells in the form of hemoglobin. Zinc and copper are found in certain proteins, while thyroid hormones triiodothyronine (T3) and thyroxine (T4) contain iodine.
Additionally, there are some elements, such as silicon, boron, nickel, and vanadium, that are considered potentially necessary for our lives. Elements like lead, antimony, thallium, and radioactive elements such as thorium, uranium, and radium are all toxic to the human body.
Finally, these 60 elements are responsible for everything that shapes our bodies, making us human!
