Schindler and colleagues428 studied serial plasma samples before, during, and up to 48 hours after surgery, demonstrating significant decreases in levels of both vitamin A and vitamin E, with persistently low vitamin E levels 48 hours postoperatively. Similarly, in the early perioperative period after CABG, reductions have been noted in levels of homocysteine and folic acid, which are part of the body s antioxidant first line of defense.429 Other studies of CABG patients have documented decreases in B complex vitamins such as B6 , and thiamine, which are essential for mitochondrial function.416,427,430 Vitamin D levels have been shown to be important predictors of outcome after cardiac surgery. In a study of 4418 patients recovering from cardiac surgery, Zittermann et al431 noted that 38.0% had deficient 25(OH)D values (<30 nmol/L). In multivariable- adjusted models, a low 25(OH)D value was independently associated with a greater risk of major adverse cardiac events, longer duration of mechanical ventilatory support and inten- sive care unit stay, and higher 6- and 12-month mortality. Intuitively, from these data, vitamin supplementation should promote a faster recovery from CABG. However, very little is currently known about the value of vitamin supplementation after cardiac surgery, and studies examining the use of vita- min supplementation in CABG patients either with or with- out specific deficiencies are lacking. Only in the perioperative period as a means of preventing postoperative AF has the role of vitamin supplementation received some attention. Given the suggestion that oxidative stress may potentiate AF, several investigators have evaluated the prophylactic administration of omega-3 fatty acids and antioxidant vitamins to reduce its incidence after CABG. 