Cholesterol is a sterol, a type of organic compound with the formula C17H28O. It is found in animals and classified as a zoosterol. Fungi have a mycosterol that performs a similar role to cholesterol, which is ergosterol.
One way to reduce cholesterol levels in the blood and lower the risk of cardiovascular disease is by taking statins, a class of drugs that act on the first 18 steps of the 37-step process the human body uses to make cholesterol.
When exposed to ultraviolet light, cholesterol undergoes a series of steps to become calcitriol, an active form of vitamin D made in the kidneys. The human body recycles cholesterol through excretion from the liver and reabsorption into the bloodstream in the small intestine.
Cholesterol is transported by astrocytes in the brain because it cannot cross the blood-brain barrier. American biochemist Joseph Goldstein discovered its role in causing heart disease and shared the Nobel Prize in Medicine in 1985 for this groundbreaking work.