The human body produces about 75 percent of the cholesterol in it at any given time. The liver is the largest internal organ in the body and is responsible for cholesterol production.
Cholesterol is a fat-like substance that has uses in nearly every cell in the body and is needed for the body to function properly. It is insoluble in blood, circulating through the blood after being encapsulated in a protein coating (the combination of cholesterol and protein coat is referred to as a chylomicron.)
The body utilizes two sources of cholesterol. One source is exogenous, or dietary cholesterol, found in fish, red meats, poultry and dairy products. Certain types of meats, such as organ meats (e.g. liver, brain) are extremely high in cholesterol. The vast majority of plant-based foods have no cholesterol in them.
The second source is endogenous, or created by the body. This process is a complex series of biochemical reactions that produces cholesterol necessary for the body to function.
Cholesterol is a major player in the human body. It accounts for portions of nearly all cell membranes in the body, and some tissues utilize more cholesterol than others. For example, the brain may use up to 25 percent of the body's total cholesterol in order to function. Energy-producing molecules such as Coenzyme Q-10 require cholesterol to be built. Without it, the body cannot produce adequate energy to power its cells.
The liver is the body's production center for endogenous cholesterol.
The liver produces roughly 1,000 milligrams of cholesterol on a daily basis. This is generally sufficient to meet all of the body's required demands.
In contrast, the average American diet contains between 200 mg and 325 mg of cholesterol, depending upon sex, race and location.