Kotur and coworkers genotyped 73 adults, hospitalized (between April and June 2020) at the Belgrade University Clinical Centre with mild (n = 35), moderate (n = 21) and severe (n = 17) COVID-19, for variants of the Dimethylglycine dehydrogenase gene (rs17823744) [39], and found that homozygous carriers of the A allele, previously associated with lower levels of serum selenium [40] and a greater increase in serum selenium following supplementation [41], had a lower incidence in patients with severe COVID-19 [39]. This evidence concerns the gene DMGDH and COVID-19.