Another important pathway, vitamin digestion and absorption, was found to be related to miR-3934-3. This KEGG pathway has been highlighted amongst others as a link between dysbiosis of the gut microbiome and chronic diseases [85]. Furthermore, intestinal triglyceride-rich lipoproteins have been related to vitamin metabolism in relation to coronary artery disease as well as viral infections [86]. In AIDS, malabsorption of vitamin 12 has been related to gastric secretory failure, including chronic diarrhoea, due to advanced HIV infection [87,88]. Additionally, vitamin A deficiency has been associated with more progressive HIV disease [89]. Veterinary viral infections, such as infectious bronchitis virus (IBV) and reovirus (RV) in chickens, have been identified to affect vitamin A metabolism due to epithelial damage [90]. Interestingly, a link between vitamin D deficiency and SARS-CoV-2 infection severity was recently reported [91]. Also, vitamin B3 was found to be highly effective to help lung tissue damage repair [92] and it was suggested to be given to COVID-19 patients as soon as the CT lung abnormalities were detected [93].