Cardiovascular disease is one of the major cause of death in worldwide. Obesity, hypertension, dyslipidemia, hyperuricemia and changes in lifestyle are the major causes attributed to Coronary Artery Disease (CAD). Various factors play a role in Coronary Artery Disease like Insulin, Vitamin–D, Calcium, Phosphorous, and FGF–23 levels in blood. The present review for the simplicity is divided into three parts and present part explains the coronary artery disease, atherosclerotic initiation, Insulin and Insulin resistance.