It is important to know that most oral vitamin B-12 supplements do not work well at all. Vitamin B-12 is the largest vitamin known; it is a very large molecule, and it is not easily absorbed. Your body has developed a very sophisticated system to absorb B-12, which involves the production of intrinsic factor in the stomach that attaches to the B-12 and allows it to be absorbed in the end of the small intestine.
If your stomach lining is damaged from an ulcer or a Helicobacter infection, you will not produce intrinsic factor very well, and you will not be able to absorb B-12 very well, if at all. An imbalance of bacteria in the small intestine can also produce impaired absorption, as would removal of a portion of the small intestine (commonly done in Crohn's disease).
Vitamin B-12 deficiency is quite common in vegetarian and vegans who do not supplement with B-12 or use fortified foods, since B-12 is not readily available, if available at all, in plants. If you are a vegetarian who eats eggs or fish, the risk for B-12 deficiency is considerably reduced, though you should still consider B-12 supplementation. If you are a vegan avoiding all animal products, and you do not already supplement with B-12 (it seems many already do), you should seriously consider it.
So, if you suspect you are deficient in vitamin B-12, I would encourage you to obtain your B-12 in a more absorbable form. The common recommendation is to use injections. My recommendation for that would be to use 1 ml once a day for two weeks and then three times a week until the 30-ml bottle is finished.
An alternative to the injections would be to use DMSO and vitamin B12. The DMSO causes the B12 to be absorbed very similarly to an injection without the cost or pain of a needle. Intranasal B12 is also available, but unless you have a prescription card I would not recommend it, as it is VERY expensive.
One strong inhibitor of vitamin B-12 absorption is the very popular drug Prilosec (omeprazole), which has been clearly shown to decrease B-12 absorption.
Maybe you can try the DMSO method or the nasal spray he suggest so you won't have to get an injection.
If you are reading this then maybe you need b-12 too. I remember you saying that you have the helicobacter infection right? So maybe B-12 would really help here.