Slightly off topic, although fully about B12 and injections. I used to frequent a Dutch forum that is purely about B12. On that forum, injections are the "bees knees" and oral is frowned upon. On this forum, it is the opposite.
That was a bit puzzling to me, to say the least. However, I think there is an explanation.
1) Product used: on the Dutch forum, they absolutely advise against cyanocobalamin - much like here. The only injections they support are hydroxocobalamin. They go as far as saying that cyanocobalamin is next to useless. For people with metabolizing problems they do advise methylcobalamin injections, but they are not easy to come by. (a couple of users sourced them from Italy IIRC)
2) Schedule: again on the Dutch forum, the preferred treatment is to start with 5 (1000mcg) injections in 10 days, then move to 2 injections a week for a month, then go to weekly, and then go to monthly injections depending on how the patient feels. Note that we are still talking about hydroxocobalamin.
If I'm not mistaken, the major beef with injections on this forum is that cyanocobalamin ones have been seen to be ineffectif and that the serum levels might swing too much when you only follow a monthly schedule.
Would people (MrsD.) here see the value of their method of choice?
Mind you, I'm not trying to say who's right/wrong. Personally, I much prefer the daily oral version as the injections are cumbersome. I'm just trying to find a logical reason as to why there is such a big difference.
PS: please feel free to move this post/discussion to the B12 thread if that's a more appropriate place.