Oxidative stress is simply defined as an excess production of reactive oxygen species (ROS) relative to antioxidant defenses. ROS, which include superoxide radicals, hydrogen peroxide, hydroxyl radicals, and singlet oxygen, are produced as a result of normal cellular metabolism (Pizzino 2017).
While often thought of in a purely negative way, ROS do serve necessary physiological functions. For instance, at low-to-moderate amounts, ROS play essential roles in the intracellular destruction of bacteria by phagocytes and some cellular signaling processes (i.e., redox signaling) (Sharifi-Rad 2020).
Problems arise when there is excessive production of ROS, creating oxidative stress. In this scenario, ROS cause cell and tissue damage. Excessive mitochondrion-generated ROS, a primary source of endogenous ROS, lead to lipid, protein, and DNA damage and are implicated in various human pathologies, including inflammation, cancer, mitochondrial and neurodegenerative diseases, diabetes, chronic diseases, and aging. In normal conditions, mitochondria are protected from ROS by multiple innate defense systems and antioxidants, including glutathione peroxidases, superoxide dismutases, glutathione (GSH), coenzyme Q, vitamins C and E, and carotene (Snezhkina 2019).
Exogenous factors also increase ROS in the body. Such factors include UV radiation, pollutants/toxins, heavy metals, certain medications, smoking, chronic disease, intense exercise, and severe life stress (de Almeida 2022). Modern exposures often tip the scales between ROS production and the body’s ability to detoxify ROS. Additional antioxidants are often necessary to create a better oxidant-antioxidant balance (redox balance).
50 to 600 mg per day (Rabanal-Ruiz 2021, Sood 2024, Hargreaves 2020)
250 to 1,000 mg per day (Schmitt 2015, Paschalis 2018, Richie 2015)
600 mg per day (Zonooz 2021, Marangon 1999, Zembron-Lacny 2009)
400 to 1,000 mg per day (Popovic 2015, Goldfarb 2005, Carty 2000)
General dosing 400-800 IU per day
Condition-specific dosing (Kemnic 2023):
Supplemental alpha-tocopherol (Ungurianu 2021):
de Almeida, Arthur José Pontes Oliveira et al. “ROS: Basic Concepts, Sources, Cellular Signaling, and its Implications in Aging Pathways.” Oxidative medicine and cellular longevity vol. 2022 1225578. 19 Oct. 2022, doi:10.1155/2022/1225578
Carty, Julie L., et al. "The effects of vitamin C supplementation on protein oxidation in healthy volunteers." Biochemical and biophysical research communications 273.2 (2000): 729-735.
Goldfarb, Allan H., et al. "Vitamin C supplementation affects oxidative-stress blood markers in response to a 30-minute run at 75% VO2max." International journal of sport nutrition and exercise metabolism 15.3 (2005): 279-290.
Jialal, Ishwarlal, Cindy J. Fuller, and Beverley A. Huet. "The effect of α-tocopherol supplementation on LDL oxidation: a dose-response study." Arteriosclerosis, thrombosis, and vascular biology 15.2 (1995): 190-198.
Jialal, Ishwarlal, and Scott M. Grundy. "Effect of dietary supplementation with alpha-tocopherol on the oxidative modification of low density lipoprotein." Journal of Lipid Research 33.6 (1992): 899-906.
Kemnic, Tyler R. and Meghan Coleman. “Vitamin E Deficiency.” StatPearls, StatPearls Publishing, 4 July 2023.
Marangon, Karine, et al. "Comparison of the effect of α-lipoic acid and α-tocopherol supplementation on measures of oxidative stress." Free Radical Biology and Medicine 27.9-10 (1999): 1114-1121.
Paschalis, Vassilis, et al. "N-acetylcysteine supplementation increases exercise performance and reduces oxidative stress only in individuals with low levels of glutathione." Free Radical Biology and Medicine 115 (2018): 288-297.
Pizzino, Gabriele et al. “Oxidative Stress: Harms and Benefits for Human Health.” Oxidative medicine and cellular longevity vol. 2017 (2017): 8416763. doi:10.1155/2017/8416763
Popovic, Ljiljana M., et al. "Influence of vitamin C supplementation on oxidative stress and neutrophil inflammatory response in acute and regular exercise." Oxidative medicine and cellular longevity 2015.1 (2015): 295497.
Rabanal-Ruiz, Yoana et al. “The Use of Coenzyme Q10 in Cardiovascular Diseases.” Antioxidants (Basel, Switzerland) vol. 10,5 755. 10 May. 2021, doi:10.3390/antiox10050755
Richie, John P., et al. "Randomized controlled trial of oral glutathione supplementation on body stores of glutathione." European journal of nutrition 54.2 (2015): 251-263.
Schmitt, Bernard, et al. "Effects of N-acetylcysteine, oral glutathione (GSH) and a novel sublingual form of GSH on oxidative stress markers: A comparative crossover study." Redox Biology 6 (2015): 198-205.
Sharifi-Rad, Mehdi et al. “Lifestyle, Oxidative Stress, and Antioxidants: Back and Forth in the Pathophysiology of Chronic Diseases.” Frontiers in physiology vol. 11 694. 2 Jul. 2020, doi:10.3389/fphys.2020.00694
Snezhkina, Anastasiya V et al. “ROS Generation and Antioxidant Defense Systems in Normal and Malignant Cells.” Oxidative medicine and cellular longevity vol. 2019 6175804. 5 Aug. 2019, doi:10.1155/2019/6175804
Sood, Brittany, et al. “Coenzyme Q10.” StatPearls, StatPearls Publishing, 30 January 2024.
Ungurianu, Anca et al. “Vitamin E beyond Its Antioxidant Label.” Antioxidants (Basel, Switzerland) vol. 10,5 634. 21 Apr. 2021, doi:10.3390/antiox10050634
Zembron-Lacny, A., et al. "Assessment of the antioxidant effectiveness of alpha-lipoic acid in healthy men exposed to muscle-damaging exercise." J Physiol Pharmacol 60.2 (2009): 139-43.
Zonooz, Sanaz Rezaei, et al. "Effect of alpha-lipoic acid on oxidative stress parameters: A systematic review and meta-analysis." Journal of Functional Foods 87 (2021): 104774.