Cholesterol is a sterol, a type of organic compound with the formula C17H28O. This substance is found in animals and is classified as a zoosterol, while mycosterol performs a similar role to cholesterol in fungi.
One class of drugs that can lower cholesterol levels in the blood and reduce the risk of cardiovascular disease are known as statins. These drugs work by targeting a pathway that involves the first 18 steps of the 37-step process used by the human body to make cholesterol.
When exposed to ultraviolet light, the body converts cholesterol into calcitriol, an active form of vitamin D produced in the kidneys. The human body has an efficient mechanism for recycling cholesterol, starting with its excretion from the liver and eventual reabsorption into the bloodstream in the small intestine.
Cholesterol is also produced and transported by astrocytes in the brain because it cannot cross the blood-brain barrier. American biochemist Joseph Goldstein played a critical role in discovering how cholesterol contributes to heart disease and was awarded the Nobel Prize in Medicine in 1985 for his groundbreaking work on this topic.