Brenda, you may not know this, and many doctors too don't know this, but lab ranges for B12 in US are VERY low reporting these lows as "normal". It is therefore necessary for patients to double check that test, themselves.

The new lowest normal now is 400 US units.
this site made for doctors, explains this:
http://www.aafp.org/afp/2003/0301/p979.html

Another factor is this: If you took cyanocobalamin and had that reaction, it could be you are not converting properly to methylB12. This is GENETIC and would run in families.
Failure to methylate folic acid and cobalamin leads to many neuro symptoms. It involves MTHFR genetic errors.
So people with this have to use methylfolate and methylcobalamin to see benefits.

The other non-methylated forms of cobalamin will show up in testing the blood, as those tests do not differentiate from the various forms.

A DNA blood test is available, for this. And also a MMA test which if elevated when adequate serum B12 is found, would indicate non-methylation of those forms. MMA is a specific test to show if B12 is actually doing its job and working.

So to be SURE you need the numbers from that B12 test. "normal" these days is just not enough.