Question: Does high B12 mean it’s not getting into the cell?The right way to address that would be to measure serum or urine or both methylmalonic acid MMA, and that's a functional marker that's very specific to B12. If B12 was not getting into the cell, then methylmalonic acid is going to be high.If you would like to be part of the next live Ask Me Anything About Nutrition, sign up for the CMJ Masterpass, which includes access to these live Zoom sessions, a private discussion group, premium features on all my content, and hundreds of dollars of exclusive discounts. You can sign up at https://chrismasterjohnphd.com/masterpass/ and use the code QANDA to get 10% off the membership for life. From now through March, I will be working full-time on finishing my Vitamins and Minerals 101 book, while reserving a portion of my time for consulting clients. You can pre-order my book at https://chrismasterjohnphd.com/book. You can sign up for a consultation at https://chrismasterjohnphd.com/consultations. DISCLAIMER: I have a PhD in Nutritional Sciences and my expertise is in performing and evaluating nutritional research. I am not a medical doctor and nothing herein is medical advice.