In 1969, McCully1 first suggested that hyperhomocysteinemia may play a role in atherosclerosis. Subsequently, there has been an explosion of research and clinical trials on whether folate or B vitamin supplementation lowers vascular risk by reducing homocysteine levels in the blood. However, evidence that homocysteine-lowering treatment with B-group vitamins lowers cardiovascular events and mortality has remained inconclusive.2 Because hyperhomocysteinemia is very common in patients with kidney failure and earlier stages of chronic kidney disease (CKD), there has been renewed interest in the possible effects of folic acid on vascular protection and progression of CKD.