Vitamin C biochemistry: From scurvy to COVID-19 treatment

The story of vitamin C (L-ascorbic acid) as an antioxidant and a cofactor in numerous biochemical reactions is a part of its long history and it is well known today. However, many questions of its mechanism of action and the benefits that it has on human health are still emerging. This applies not only to the recommended doses but also to the route of its administration. Besides, there are numerous questions about the therapeutic efficacy of vitamin C in various human (infectious) diseases, as well as its immune system function and antiviral potential. The fact that vitamin C can act as a reductant (antioxidant) and a prooxidant further emphasizes its oxidation-reduction (redox) potential in real physiological conditions. Today, the question of the intravenous administration of vitamin C effect in patients with SARS-CoV-2 requires special attention. This review aims to showcase known facts about vitamin C and its mechanisms of action to better understand the current new challenges related to vitamin C.