Pistachios are rich in potassium (helps regulate the body's fluid balance), phosphorus (helps build bones and teeth) and magnesium (important element in the conversion of the body's energy), and are also a good source of vitamin B6 (aids protein metabolism and absorption) and thiamine (enhances energy and promotes normal appetite). These nuts also have a relatively low calorie value when compared to other nuts and are cholesterol free, high in fiber and low in saturated fat. These nuts are also a very good source of protein.