Dr. Amy Nett: So in the setting of high serum B12, you would also want to look at, this is where MMA comes in handy. If you have access to whole OTC, you can measure that, you can also consider doing functional methylation testing. Remember also to look and see if there’s anemia because if there’s a functional B12 or folate deficiency, then you’re going to see evidence of anemia with a large MCV. So those are all going to be clues. In terms of treatment, well, you might want to do, it depends.
If the patient has low active B12, think about supplementing with those forms of B12 that we talked about. And again Chris talked about the three different forms of active B12 and we generally use Trifolamin if we just want to do a B12 and folate supplement. So you could try supplementing, preferably with a sublingual lozenge so you don’t have to rely on oral absorption. And also we occasionally use lithium orotate. That seems particularly helpful in terms of getting B12 into the brain.