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Neuroscientist 24 , 186200 (2018)

The bacteria eat this vitamin and produce a molecule that is similar to the structure of B12 this molecule competes with vitamin B12 receptors, resulting in decreased absorption of B12

doi: 10.1186/s12943-024-02030-x

The NAD stated that while it recognized that in vitro studies can provide some background evidence about a substance, suggesting further clinical research, in vitro studies are of limited value in predicting the effect of a substance when consumed by humans and in most cases such studies cannot by themselves support health claim[s]. With respect to pilot clinical studies, the NAD stated, Generally speaking, a pilot study is a small-scale preliminary study conducted to evaluate feasibility, time, cost, adverse events, and effect size (statistical variability) for further research. The NAD expressed concern about the reliability of extrapolating information from preliminary findings to support performance claims