11 are necessary for life and were produced in many stars, the carbon from your left hand could be from a different star than your right hands! 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.
RE: We are all Star Dust - Carl Sagan