Most remarkably, VitC enhances the activity of a specific class of RNA and/or DNA demethylases, that is, the human AlkB homologue enzymes (VitC/Fe+2/αKG-dependent dioxygenases) [29, 30], including ABH1 (or ALKBH1), which catalyzes the demethylation of 3-meC in DNA and RNA [31]; ABH2 (ALKBH2), which catalyzes the oxidative demethylation of 1-methyladenine [32]; ABH3 (ALKBH3), which repairs methylated RNA [33]; and FTO, which demethylates 3-methylthimidine (3-meT) and 3-methyluracil [34], whose variants were found associated with obesity in both children and adults [35]. Here, ALKBH3 is linked to obesity due to melanocortin 4 receptor deficiency.