Human Body

Introduction and Historical Background

Which chemicals constitute the human body?

About 24 elements are used by the body in its functions and processes.

Major Elements in the Human Body
Element Percentage Function
Oxygen 65.0 Part of all major nutrients of tissues; vital to energy
Carbon 18.5 Essential life element of proteins, carbohydrates, and fats; building blocks of cells
Hydrogen 9.5 Part of major nutrients; building blocks of cells
Nitrogen 3.3 Essential part of proteins, DNA, RNA; essential to most body functions
Calcium 1.5 Forms nonliving bone parts; a messenger between cells
Phosphorous 1.0 Important to bone building; essential to cell energy

Potassium, sulfur, sodium, chlorine, and magnesium each occur at 0.35 percent or less. There are also traces of iron, cobalt, copper, manganese, iodine, zinc, fluorine, boron, aluminum, molybdenum, silicon, chromium, and selenium.


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