Paul Saladino· MD
you want the B12 level to be between 300 and a thousand nanograms per liter sometimes you'll ask me what happens if I have a B12 greater than a thousand nanograms it's not an issue in most people because they're eating a lot of meat hemoglobin levels greater than 13 grams per deciliter serum ferentin concentration is greater than 70 nanograms per milliliter or greater