Anybody with B12 malabsorption issues can use our B12, whether that's due to pernicious anemia, tapeworm infection, sleeve gastrectomy or gastric bypass surgery, etc. That being said, pernicious anemia patients can especially benefit from methylcobalamin, since they cannot metabolize B12 like normal people, and so they absolutely need a native form. Also, they commonly have other comorbidities like impairment of the methylation cycle, which leaves them with extremely high and harmful levels of homocysteine, which methyl B12 helps reduce.