I've been getting b12 injections for four days now. I am having some adverse reactions (rapid heartbeat, acne, shortness of breath, itching, when I wake, I have an anxious feeling and weakness/brain fog). I am not going to take any more injections, but I'm wondering, how long does it take for the b12injections leave my system?

The injections were likely cyanocobalamin, which stays in the bloodstream only a short time - less than a week (though B-12 is stored in the liver for several months).

http://www.nature.com/nature/journal.../198200a0.html

After you feel recovered, you might consider trying sublingual methylcobalamin.

http://neurotalk.psychcentral.com/thread85103.html

HTH,

Doc

My blood test for B12 came back at 1200 being the highest level shown. I've been taking 5000mcg bilingual B-12 meth for sometime. Should I cut down on my daily dosage seeing my test came back at the highest level? I don't think my doctor really knows the answer.

--for any health related reason that I know of--B12 has no known toxicity level, as the body uses what it needs and excretes excess.

You may be creating some very expensive urine if your body is taking in far more than it needs, but that's the only caveat I would have.

I suspect that if you're taking 5000mcg/daily, your serum B12 level would be much higher than that if the lab that did the measurement uses a methodology that allows for higher values. (My last measurement was 1672. But I do heavily supplement, as you do. I often have to explain this to doctors.)

The real key, I suppose, is how do you FEEL at this dose? Are you having improvements?

Hi KittyKatty.
Nice to meet you here at Neurotalk.

Do you actually mean you've had the injections 4 days in a row or 4 injections over a period of a couple of weeks or so?

A lot could depend on why you have been prescribed this medication in the first place. Hard to know from your post.

Hope you're ok.

We know what you meant - I get days like that too....

Originally Posted by Rosie33
I've been taking 5000mcg bilingual B-12 meth for sometime. ....
That was actually a "TEST" to see who was paying attention, and YOU win first prize....a week in sunny Mexico ....so there!

I feel pretty good but I've developed a light red rash on my arms and legs, and thought I would stop all vitamins and supplements for a few days to see if it's an allergic reaction. I've also been following a gluten free diet for the past couple of days. The rash is not itchy but it's driving me crazy because I've had it about 2 weeks now. I have an appointment next week with my doctor.

I would continue what you are doing. There is no documented high toxic level for B12. The highest that is testable, as reported on the net by people working with the machines...is 2000.

If you go to my B12 thread, post 70 explains from Dr. Snow, why some people with neuro problems may need more, than others.

Some people react to cyano form which is the common form in most injections. That is a form of cyanide, and often cannot be metabolized away by rare patients.