Composition of the Human Body

Element Mass of element
in 70kg person
oxygen 43 kg
carbon 16 kg
hydrogen 7 kg
nitrogen 1.8 kg
calcium 1.0 kg
phosphorus 780 g
potassium 140 g
sulfur 140 g
sodium 100 g
chlorine 95 g
magnesium 19 g
iron 4.2 g
fluorine 2.6 g
zinc 2.3 g
silicon 1.0 g
rubidium 0.68 g
strontium 0.32 g
bromine 0.26 g
lead 0.12 g
copper 72 mg
aluminum 60 mg
cadmium 50 mg
cerium 40 mg
barium 22 mg
iodine 20 mg
tin 20 mg
titanium 20 mg
boron 18 mg
nickel 15 mg
selenium 15 mg
chromium 14 mg
manganese 12 mg
arsenic 7 mg
lithium 7 mg
cesium 6 mg
mercury 6 mg
germanium 5 mg
molybdenum 5 mg
cobalt 3 mg
antimony 2 mg
silver 2 mg
niobium 1.5 mg
zirconium 1 mg
lanthanium 0.8 mg
gallium 0.7 mg
tellurium 0.7 mg
yttrium 0.6 mg
bismuth 0.5 mg
thallium 0.5 mg
indium 0.4 mg
gold 0.2 mg
scandium 0.2 mg
tantalum 0.2 mg
vanadium 0.11 mg
thorium 0.1 mg
uranium 0.1 mg
samarium 50 µg
beryllium 36 µg
tungsten 20 µg
Oxygen is the most abundant element in the earth's crust and in your body. The 43 kilograms of oxygen are found in the body's water (which makes up 70% of total body weight), proteins, nucleic acids, carbohydrates, and fats.

Rubidium is the most abundant element in the body (0.68 g) that has no known biological role (silicon, which is slightly more abundant, may or may not have a metabolic function).

Vanadium is the body's least abundant element (0.11 mg) that has a known biologic role, followed by cobalt (3 mg), which is a constituent of vitamin B12.

 

 

This number line shows the relationship between the mass units used on the table.