Vitamin D3 is reported to contribute to the prevention of some chronic diseases, such as diabetes (Gren 2013) and cardiovascular disease (El-Gohary and Allam 2017) by regulation of oxidative stress via increasing the antioxidant enzymes, such as glutathione peroxidase (GPx) and SOD, and suppressing the expression of NADPH oxidase. The gene discussed is SOD1; the disease is diabetes mellitus.