A steroid found in all cells and plasma. Cholesterol is an essential lipid that is obtained through diet and produced in the liver. It is essential for life but can be harmful if levels are too high. It helps to form cell membranes and is used in the production of hormones, vitamin D and bile salts. Levels may indicate oxidative stress, inflammation, insulin resistance, blood glucose dysregulation, poor thyroid function, magnesium deficiency, dehydration, liver or kidney dysfunction or familial hypercholesterolemia., heavy metal load, adrenal sufficiency, gallbladder function.