Coenzyme Q10 is a naturally occurring compound in blood and tissues. It is also a readily available dietary supplement often used as an alternative and complementary medicine. It is a powerful antioxidant. Previous studies have shown that blood levels of coenzyme Q10 are decreased in hemodialysis patients. Because of this, it is important for us to find out if giving coenzyme Q10 to hemodialysis patients can help prevent CVD. However, at present, there are no studies which carefully look at the safety and tolerability of coenzyme Q10, and whether it helps stops the harmful chemical reactions in the blood.