B12 low, treated but...: Hello, I have... - Pernicious Anaemi...

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B12 low, treated but...

Lorilee60 profile image


I have been having awful symptoms for about a yea, worsening as time went on. My pPCP, neurologist, and even bariatric dept missed this for months. I had gastric bypass surgery 10 years ago, so this didn't completely surprise me (B12 issues), however it was never completely explained to me the gravity of what that could mean. I ended up self referring to the Mayo Clinic because all I was getting locally is that I have migraines. 56 years old and never had migraine in my life until a year ago. My B12 was 180 but had numerous neurological issues. I received an injection in early May and 3 weeks later went to dr. And they ordered 2 injections a week for 3 weeks. That ended Friday. Today had my B12 tested and it was 1535, which is much higher - too high? I go back to the PCP on Wednesday, and I am afraid he will look at that level and tell me I am good for a month...I do know eventually I will be on once a month for life. What I do not know, is the normal routine to go from loading dose to monthly, or is it better to go to weekly or bimonthly to begin with? I am in the U.S.

Thank you

Note from Admin: This post is now closed to further replies due to some unhelpful responses relating to cyanocobalamin. Like all forms of B12 cyanocobalamin doesn't necessarily suit everyone but some people do find it very effective

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12 Replies
clivealive profile image
clivealiveForum Support

Hi Lorilee60 I can't answer your question about American routine but I'm guessing that you will be on cyancobamalin every four weeks.

It is generally considered unnecessary to test B12 levels after treatment has commenced - unless it comes back very low. You cannot overdose on B12 as any excess is excreted via your urine.

Just one quick point - do you know what your Folate level is?

There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be "masked" by excess of another so the three must always be in balance.

Folic acid works closely with vitamin B12 in making red blood cells and helps iron function properly in the body.

I am not a medically trained person but have had P.A. (a form of B12 deficiency) and been on cyanocobamalin injections every four weeks for over 45 years.

I hope you soon start to feel better and wish you well.

Learner1 profile image
Learner1 in reply to clivealive

Folate, not folic acid. Many people can't process folic acid which can build up to toxic levels. Everyone can make use of 5-methyltetrahydrofolate.

Theres really no way of overdosing on B12. The test you want to determine sufficiency is a methylmalonic acid test. The serum B12 will look high if you supplement. MCV is another marker, if its over 95, you're low in either B12cor folate.

According to the Mayo Clinic, people typically store 3-5 years worth of B12. If you've depleted that store and are low, its unlikely a couple shots will replenish it.

As you mentioned, doing shots 1-3 times a week over a period of time is prudent. It might be best to avoid cyanocobalamin, which has a cyanide molecule to detox and use methylcobalamin maybe with some hydroxocobalamin, ideally with a B complex.

Foggyme profile image
FoggymeAdministrator in reply to Learner1

Learner1. For clarification...there is no superior form of cobalamin...and no reason to avoid cyanocobalamin (as per Hidden 's comments).

Research paper:

ncbi.nlm.nih.gov/pmc/articl... (No Superior Forms of Cobalamin)

Learner1 profile image
Learner1 in reply to Foggyme

Thank you for the textbook chapter. If you actually read it, you will find that in many cases, patients cannot make the conversion to the active forms, methyl and adenosylcobalamin.

"Defects in MMACHC (cblC gene) lead to inability to synthesize MeCbl and AdoCbl from supplemental CNCbl"

As someone who needs 10mg of methylcobalamin a day, and has genetic SNPs affecting my B12 processing, I've found it best to actually solve the problem and get the active forms into me.

And, as someone who has dealt with mercury, lead, arsenic, cadmium, and platinum toxicity, where B12 is essential in Phase 2 detoxification, it seems risky to invest a known toxin, cyanide, which my already stressed body will need to detoxify. And taking larger doses exposes us to more cyanide than someone taking it in a daily multivitamin.

Textbooks have their place, but as real patients, who are unique genetic individuals with unique environmental exposures, its prudent to weigh the risks for ourselves before using "cookbook medicine" based on generic patients.

Foggyme profile image
FoggymeAdministrator in reply to Learner1

Learner 1.

'Textbook Chapter' and 'Cookbook Medicine'?

Note: RESEARCH PAPER - Scientific research, underpinned by scientific research. Peer reviewed. Published: National Centre for Biotechnology Information.

Learner1 profile image
Learner1 in reply to Foggyme

We are all unique genetic individuals with unique environmental influences which will make a dramatic difference in how we are treated.

That's why a one size fits all approach won't work, and can, in fact, be dangerous.

Some of us need 5-MTHF and methyl, adenosyl or hydroxo B12, and can be harmed by the cheap, synthetic forms of these vitamins.

It is wise to know about this and not suffer the consequences because of ignorance or a one size fits all mentality.

Foggyme profile image
FoggymeAdministrator in reply to Learner1

Thank you for that Learner1 but I think you're missing the point (or should I say two points).

1) no reason to exclude cyanocobalamin from the range of B12 treatment options - some people actually do better on this than other forms of cobalamin.

2) This forum does not (ever) advocate a one size fits all approach to the treatment of pernicious anaemia.

Gambit62 profile image

high levels of B12 are normal after injections. as clivealive says serum B12 doesn't really mean a lot after treatment with injections and it is much more important to monitor and respond to symptoms.

I'm not sure that there is a standard routine for loading shots in the US - weekly seems to happen quite often - for about 8 weeks and then on to monthly going from reports on this forum over the last couple of years.

In the UK loading shots with neurological involvement would be 3x per week until symptoms stop improving (review at 3 months). Not sure if this is the protocol that is recommended in Could it Be B12? by Sally Pachalok et al but if you haven't looked at it, it would probably be good to arm yourself with it - it was written primarily to get messages on b12 awareness over to doctors so might be worth giving a copy to your PCP if they aren't up on B12.

Hi Lorilee,

I am in the US as well. It is totally normal for maintenance doses to be done once a month. However, you do need loading doses for longer then you got. Where in the US are you, and are seeing a hemotologist? Some people neede shots one a week or twice a month, it depends on the individual. Find yourself a good hematologist that will allow you to work together to guide your treatment, mine does and I feel better. Good luck!

One doesn't need a hematologist to get B12 shots. Any doctor can prescribe it. A functional medicine doctor would be a good choice, if you're seeking out someone with expertise.

I'm in the US and have been getting 5mg shots 3x a week for a year and have still been low.

Likely none of those patients are on this site. They likely wouldn't make much use of cyanocobalamin either.

Here's some advice to pharmacists:


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