In mild cases, or when methylene blue is ineffective or contraindicated, such as in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, ascorbic acid may be used as an alternative or adjunctive reducing agent, as it promotes the slow nonenzymatic reduction of methemoglobin independently of NADPH (nicotinamide adenine dinucleotide phosphate) availability [6,8-10]. The gene discussed is G6PD; the disease is G6PD deficiency.