I used to have pains in my arms, as well as really bad back pain, dizzyness, lack of concentration etc. So I started taking B12 - about 250 - 500 mcg per day, of cyanocobalamin under the tongue, which has made the pain in my arms go away, but now I believe that it may be causing psychological side effects, such as paranoia and anxiety.

Has anyone else had this problem? Or could this be my potassium going down that is causing this anxiety?

If you were anemic at the time you started B12, increased cell formation of blood cells, can cause a temporary decrease in potassium. This can be felt as tiredness and/or cramping of muscles.

However, it is a brief period, of time, and does not continue once the red cell count normalizes. B12 is used by all the body's tissues, and will go where needed.

There are people who have mental symptoms when methylation is not working properly in the body.
Here is an article about it:
http://www.alternativementalhealth.c...es/walshMP.htm

This one discusses methylation also and explains pyroluria, which also causes anxiety. (low B6 and zinc).
http://jdmoyer.com/2011/09/03/b-vita...s-complicated/

Thank you so much for your response, Mrs D.

Is it possible to not be able to process cyano B12, but to properly process the injections (hydroxocobalamin)?

Or is it possible to not process cyano but be able to process Methylcobalamin?

It is possible to not be able to process cyano form.

But those people usually can process Methyl and hydroxocobalamin.

Sometimes when people fix low levels, there are adjustment times, when things are not quite fixed but misfiring.

It is difficult to say for you however...because everyone is different.

Thank you for your quick response, Mrs D.

It's hard for me to know whether I'm unable to process cyano, or whether things are just adjusting. I wake up after being asleep at night for an hour or two and feel very dizzy and sick, delusional and like I'm going to die. I thought that if the B12 was helping me then I would feel better. I have a gut feeling that I'm not processing cyano very well, even though it made my pins and needles go away.

Have you had your heart checked?

Some A-fib attacks can cause distressing symptoms.