Why would he be against it? There is no upper limit for B12 by the FDA ...no known toxicity ever reported!

Here is Dr. Snows article...
http://neurotalk.psychcentral.com/post698522-70.htm

Doctor's get used to reading lab reports....with those red flags for out of range.... There really is no UNsafe upper limit for B12 but they flag it anyway. So seeing red=unsafe to many doctors, who are not really educated on B12.

I got my range to 1999 in 3 mon from 850 using Puritan's Pride 5mg methyl B12. Most labs do not have equipment to read above 2000 in the US.

If you need it you should get it. B12 is OTC and since it is benign you can decide what to do yourself. Taking on an empty stomach is very important. Only a tiny part of oral B12 ends up in your bloodstream...the rest is not absorbed.

B12 will enhance the making of red blood cells. This uses up iron.
High sudden enhanced red cell making may lower potassium, so eating potassium rich foods is a good idea. This only happens in people really low however, when they start B12 therapy.