Source: O'Leary, F., & Samman, S
Its always a good idea to ask about these upfront
High-dose oral B12 can even help overcome mild absorption problems, as some of the vitamin is absorbed passively
Some practitioners implement cycling to theoretically prevent receptor desensitization, provide physiological breaks, or manage costs, though evidence supporting these approaches is limited
Research published in Science Translational Medicine (2015) demonstrated that elevated B12 levels can alter the gene expression patterns of these bacteria, specifically downregulating genes involved in B12 synthesis within the bacterial cells
Side effects were dose-dependent and transient