What are three most common elements that make up the human body?

Oxygen

Phosphorus

Hydrogen

Carbon

Nitrogen

Calcium

The three most common elements are oxygen, carbon, and hydrogen

Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life.