I think it is different for each person, I had my 2nd surgery in 1995 and didn't start getting b-12 injections until I was pregnant in 1996. Although I have had anemia problems in iron infusions all a long.
However, I will NEVER give up my b-12. I can tell at the beginning of each month that I need them. My husband (who has no medical training) has learned how to give them to me. They are cheap also, with my insurance now I pay a whopping $.53, yes that's right but when my old insurance didn't cover them the were only about $8/mo. It's worth it.
Mickey
