Is pernicious anemia helped by b12 vitamins as well as as b12 injections?

Maybe: If B12 deficiency is caused by a lack of something called "intrinsic factor, " then you may not be able to absorb orally ingested B12 very well. Under these circumstances it's sometimes preferable to do injections, especially at first. On the other hand, very high dose oral B12 can sometimes do the trick, but response will probably be slower.

Most true B-12: Deficiencies are due to loss of "intrinsic factor", secreted by the stomach, it aids absorption, so if it is missing pills will not work. Shots of b-12, cyanocobalamine, are bright red, and are used for placebo effect in some instances. Most people have intrinsic factor, normal b-12 levels.