Cholesterol is an important sterol, that is required for animal cells to function correctly, and which is used in tissue repair, strengthening cell membranes and influencing their membrane fluidity, manufacturing bile salts, as a precursor to steroid hormones (including estrogen, testosterone, cortisone), and as the raw material for the production of vitamin D.
Despite these values, cholesterol has a poor public image as a result of its role in influencing cardiovascular illness in humans. However, key factors in dealing with this problem is personal responsibility—specifically, diet and exercise, such as reducing or eliminating foods high in fat, or practicing a low glycemic diet, and/or regular exercise. All physical substances have the potential for being dangerous at high levels, as seen in the fact that one can drown in water. Cholesterol is an example of a natural substance that has a vital role, but which lack of personal dietary discipline, as seen in the epidemic of obesity, are resulting in an exacerabation of its potential harmful effects.