The two factors that affect the gravitational force between two  objects are Mass and Distance.   The mass of the two objects and the distance between them according to Kepler's Law Fg = GMm/d^2. Gravity exerts itself between all bodies in the universe. It is related to the mass of the bodies and the distance between them.
Note: none of these elements exists freely; all are found chemically combined with other elements in compounds. Although there are over 100 elements, only 12 or so are used to make biological materials. Living organisms are built predominantly from non-metal elements.
By comparison, the human body contains 43 kilograms of oxygen, the most abundant element in the earth, as well as the human body. Other elements found in the human body include 16 kilograms of carbon and 7 kilograms of hydrogen.