Four years ago, I was at the top of my game. I was participating in Ironman Triathlon events, getting my master’s degree, and trying to be the best, most organized, never-missing-a-beat, mom and wife possible. Then, in no time flat, I went from Ironman triathlete to woman in a wheelchair.

While anyone can suffer from a vitamin B12 deficiency, autoimmune patients are especially susceptible. A B12 deficiency is almost a given for people with Pernicious anemia, Crohn’s disease, Graves’ disease, and lupus.