Even if you are getting shots of B12 you may want to take pills too. That may keep your B12 at a more constant level. Many of us take at least 1000mcg of methylcobalamin every day.

There is evidence that oral B12 does as well as injections and is certainly less expensive. http://www.aafp.org/afp/20060101/cochrane.html#c2

In Sweden high dose oral B12 is used more often than injections. http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

Anne