Vitamin C is an essential micronutrient for humans. It is a potent antioxidant and a co-factor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C deficiency results in impaired immunity and higher susceptibility to infections. In turn, infections significantly impact vitamin C levels due to enhanced inflammation and metabolic requirements. Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections.
