Elements in the Human Body

We all know about the different elements (types of atoms) found in the universe. What many people aren’t aware of, however, is how these elements are utilized by the human body. The following table will inform you how much of the body (by mass) is composed of each element.

Percentage of Body WeightElementUsage
65%OxygenThis element is obviously the most important element in the human body. Oxygen atoms are present in water, which is the compound most common in the body, and other compounds that make up tissues. It is also found in the blood and lungs due to respiration.
18.6%CarbonCarbon is found in every organic molecule in the body, as well as the waste product of respiration (carbon dioxide). It is typically ingested in food that is eaten.
9.7%HydrogenHydrogen is found in all water molecules in the body as well as many other compounds making up the various tissues.
3.2%NitrogenNitrogen is very common in proteins and organic compounds. It is also present in the lungs due to its abundance in the atmosphere.
1.8%CalciumCalcium is a primary component of the skeletal system, including the teeth. It is also found in the nervous system, muscles, and the blood.
1.0%PhosphorusThis element is common in the bones and teeth, as well as nucleic acids.
0.4%PotassiumPotassium is found in the muscles, nerves, and certain tissues.
0.2%SodiumSodium is excreted in sweat, but is also found in muscles and nerves.
0.2%ChlorineChlorine is present in the skin and facilitates water absorption by the cells.
0.06%MagnesiumMagnesium serves as a cofactor for various enzymes in the body.
0.04%SulfurSulfur is present in many amino acids and proteins.
0.007%IronIron is found mostly in the blood since it facilitates the transportation of oxygen.
0.0002%IodineIodine is found in certain hormones in the thyroid gland.


There are many other elements found in the human body, but their presence is largely insignificant when compared to these other elements.

Return to the Physiology Articles Section

Other Articles That You May Be Interested In:

Mitch Hedberg
With a unique brand of humor, Hedberg became a successful comedian
Cape Fear Movie Review
A review of Scorsese's remake of the classic film.