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.
Mass of element. in a 70-kg person. Oxygen is the most abundant element in the earth's crust and in the body. The body's 43 kilograms of oxygen is found mostly as a component of water, which makes up 70% of total body weight. Oxygen is also an integral component of all proteins, nucleic acids (DNA and RNA), carbohydrates, and fats.