Re: High b12
Glomelular Filtration Rate(GFR) has to do with the kidneys, but I don't remember the specifics. For clarification, B12 is a vitamin, and iron is a mineral. If each is low, they can make us anemic. But, if you are low on iron, you have iron deficiency anemia and take iron to get out of it. If you are b12 deficient, you have pernicious anemia, which is a whole other ball game. It tends to give more neurological symptoms. As far as your tests, I don't know about the low saturation, just assume it would be better to have a higher number!