What is the most common element in the human body?

The most common element in the human body is oxygen, which makes up about 65% of the total weight of a human. Other elements that are important in the human body include carbon, hydrogen, nitrogen, calcium, and phosphorus.

Oxygen is essential for cellular respiration, the process by which cells produce energy. It is also a key component of DNA, proteins, and other important molecules in the body. Carbon is the basis of all organic molecules in the body, including carbohydrates, lipids, proteins, and nucleic acids. Hydrogen is an important component of water and many organic molecules. Nitrogen is a key component of proteins and nucleic acids. Calcium and phosphorus are important for the structure and function of bones and teeth.