Vitamin C megadosage Based on that study, the American Burn Association (ABA) considers high-dose ascorbic acid an option to be considered for adjuvant therapy in addition to the more accepted standard treatments. Atrial fibrillation (AF) is a common cardiac rhythm disturbance and it is associated with oxidative stress. Four meta-analyses have concluded that there is strong evidence that 1-2 g/day of vitamin C before and after cardiac operations can decrease the risk of post-operative AF. However, five randomized studies did not find benefit in the USA, so that the benefit was restricted to less wealthy countries. Exercise-induced bronchoconstriction (EIB) indicates acute narrowing of
Vitamin C efficiency decreases as amounts increase. Intravenous administration bypasses this. Doing so makes it possible to achieve plasma concentrations of 5 to 10 millimoles/liter (mmol/L), which far exceed the approximately 0.2 mmol/L limit from oral consumption. The theories of mechanism are contradictory. At high tissue concentrations ascorbic acid is described as acting as a pro-oxidant, generating hydrogen peroxide (HO) to kill tumor cells. The same literature claims that ascorbic acid acts as an antioxidant, thereby reducing the adverse effects of chemotherapy and radiation therapy. Research continues in this field, but a 2014 review concluded: "Currently, the use of high-dose intravenous vitamin