Its found in animal products such as dairy products, eggs, fish, and chicken, as well as fortified cereals and nutritional yeast
doi: 10.1016/0014-5793(95)00763-Y
It is noteworthy that such beneficial effects (counteraction of increased MDA values along with the distinctive effect on NO and eNOS) and a general lack of toxicity [3,4,5,6,7,8,9,10,11,12,13,14,16,17,18,19,20,21,22,23,24,27,28,29,30,31,32,34,37,39,40] would also be instructive for all metabolites, and therefore metabolites would also participate in the noted beneficial effects (see Section 1)
We always recommend getting labs done to determine if you are truly deficient in B12 and if supplementation is necessary
(PubMed) Ravaglia G, Forti P, Maioli F, et al
Cognitive performance research suggests that IV NAD+ might enhance various cognitive functions beyond typical practice effects [19]