Can vitamin B12 become addictive? Can... - Pernicious Anaemi...

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Can vitamin B12 become addictive? Can you become dependent on them?

Do any of you believe or have some evidence that vitamin B12 can become addictive? By "addictive" I mean more of a dependence. I read about various persons in this forum and I know one from work that use at least 1000 mcg of B12 on a daily basis. Now, I understand people with Pernicious Anemia (PA) that have an absorption problem may need frequent injections, I'm not talking about them. I'm talking about otherwise healthy people that can't get out of bed unless they spray their mouth with sublingual B12. I can imagine our bodies having some sort of regulatory mechanism that reduces absorption in the presence of megadoses, and there's no question that 1000 mcg is a megadose. Even with PA you should not need daily megadoses as far as I'm concerned. It might be wise to gradually diminished any vitamin/mineral supplementation once the deficiency has been resolved. I think that supplementation beyond what is obtainable in nature could cause some trouble in the long run. For example, its practically impossible to naturally consume 1000 mcg of vitamin B12 just from food. And even if that were possible, absorption thru the intestines is usually just a percentage of that. Now I don't have any studies or medical literature to back this up, but the lady I know from work really concerns me so much. She cannot go a single day without her megadose of B12. I've looked around in the internet but there's nothing about vitamins being "addictive". I found this reference, its not what I'm talking about but its similar: "Vitamin dependency results from a genetic defect involving metabolism of a vitamin. In some cases, vitamin doses as high as 1000 times the DRI improve function of the altered metabolic pathway."


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39 Replies

B12 is water soluble and your body pees away the excess so one can’t overdose so why is anyone talking about “1000 mcg megadoses”A good steak may be a megadose under those ideas.

If a person’s hepatic loop storage mechanism is working there should be no issue.

The fact that oral supplements or an energy drink gives a person a boost typically indicates that the gut is absorbing the vitamins.

I have an absorption issue so may not be the right person to answer this but I’ve had improved sleep and better circadian rhythms with my regular B12 regime. I wouldn’t call that a dependency or an addiction. I get some benefits from oral supplements and eating meat but still need weekly cyano injections. I take 4x 5000 mcg methyl sublinguals a day to keep going and fill in when needed.

I find it hard to get going sometimes.

Some people need a good high protein breakfast others need breakfast cereals (fortified with >RDA amounts of vitamins).

How old is your friend? Stress filled life style?

in reply to pvanderaa

Don't know her exact age but she's between 50 and 60. She's a customer who I chat a lot with. I suppose there might be some placebo to it. They say that you store B12 for 2 to 3 years...why doesn't her body "fill up" on B12 for the next few years? Right now I'm supplementing and I don't want to get to that point where I have to spray my mouth with B12 every morning because otherwise I feel horrible. Pvanderaa, how long have you used B12? Thanks for the information.

pvanderaa profile image
pvanderaa in reply to

I had stomach surgery in 1993 and the B12 deficiency didn’t show up until 2008. The doctor never said it needed to be monitored or that I needed supplements.

I’ve been on hydroxo injections in the UK until 2010 and then on cyano in the USA following the move.

I now also supplement with methyl sublinguals and take these during the day about 30 minutes before meetings to clear my brain fog and during my evening commute to replenish any loss from the stress during the day.

I’ve also taken methyl before bed occasionally if I’ve forgot to take the dose earlier in the day. I find it helps improve my dreams and I feel more refreshed from my sleep. I've been stable for 8 years now and continue to see very slow improvements to any nerve damage.

I’m off all alcohol and have a celiac and sugar free diet.

I’ve come to realize that anyone over 50 should be supplementing with B12.

in reply to pvanderaa

I hope you recover as soon as possible. Many people with stomach surgery suffer from B12 deficiency. Most don't realize it until the have serious issues. Thanks.

pvanderaa profile image
pvanderaa in reply to

That was my situation. Ended up nearly psychotic, with short term memory loss and a right leg that wanted to do its own thing when I walked before the B12D was diagnosed.

10 years on:

Leg is much better.

Psychosis is gone.

Balance is good.

Still have some short term memory issues and occasional lack of discretion or judgement when trying to make decisions.

Long term memory was never impacted.

Vagus nerve seems to be working as well.

shaylynn profile image
shaylynn in reply to pvanderaa

Hi pvanderaa, just curious... do you take the 4 sublinguals a day and inject as well, or do you get what you need with that high dose of b12 a day?

pvanderaa profile image
pvanderaa in reply to shaylynn

I spread the 4x methyl sublinguals along with 6x 800 mcg folic acid in three doses throughout the day. Typically morning, lunch and my evening commute.

I inject half my weekly cyano dose on Monday morning and the other half on Thursday.

Due to my absorption issues, I consume B12 and don’t recycle it. By spreading out the treatments I get a fairly continuous supply for my body to function more or less normally.

Taking megadoses of oral B12 is totally pointless. The normal absorption mechanism is saturable, it can only handle about 13 mcg in a single meal.

Gambit62 profile image

addiction is generally defied as persisting with a behaviour that is harmful.

B12 is not toxic.

Although it is possible for high serum B12 to result in a functional B12 deficiency (not enough getting into the cells for processes to run properly) the most effective way of treating this is to raise B12 levels and keep them high.

Unfortunately functional B12 deficiency tends to be associated with B12 levels being reduced by by kidneys removing the excess much slower, so waiting for levels to reduce could be potentially harmful.

On one level the notion of being addicted to B12 is akin to being addicted to breathing

in reply to Gambit62

What I meant is how is it that some people need daily 1000 mcg of B12. A person recovering from deficiency would definitely need it. But at some point I would imagine that their body becomes normal again to the point where eating meat is sufficient. My friend from work is just stuck in that state where she will need B12 spray for the rest of her life. Of course I don't know all the facts. Maybe she doesn't metabolize B12 like in the link I provided. I read somewhere that if you have liver disease, you body does not store B12, so this might cause you to need so much daily B12. Thanks for the info.

bdole2018 profile image
bdole2018 in reply to

Aside from an intrinsic factor deficiency due to antibodies: There are a plethora of conditions that can impair or almost outright prevent b12 absorption.

These do not simply go away just because the regular levels have been restored. This is why b12 injections are for life once intrinsic factor antibody comes back positive according to the NICE clinical guidelines etc.

Furthermore there is no way to tell how much the body will store and or utilize from serum b12 blood testing.

Further to this; b12 injections tend to have a stimulating effect especially in the chronically sick with conditions that can often accompany PA. So it's not surprising that some people inject daily.

If it works and helps avoid having to consume 1/2 pound of raw liver daily to get the b12 and intrinsic factor then what is wrong with it?

in reply to bdole2018

I'm not saying there is anything wrong with daily supplementation. But what if you have a stroke and are hospitalized for 3 months (I've know of this happening to someone). I don't know of any hospitals that will supplement their patients in a coma with daily 1000 mcg of B12. By the time you get out of the coma, you will be in a severe state of neurological damage since you skipped your daily B12 for 3 months. My concern was that since I'm currently supplementing orally (just finished my injections), I don't want to end up like my friend where I have to keep a spray bottle of sublingual B12 next to my bed.

pvanderaa profile image
pvanderaa in reply to

If you have a B12 absorption issue or a recycling issue then you pretty much will be on B12 injections and supplements for life.

If blood test results show normal range for B12 while on injections, many Drs are tempted to say “your better now” and remove the injections altogether or replace them with oral supplements.

The danger is that neurological damage starts up almost immediately but can be masked by supplementing folic acid or multivitamins.

Symptoms return eventually if there is an real issue in the gut or recycling mechanism in the hepatic loop or even uptake of B12 within the cells of the body.

I occasionally forget my injection or supplements and within the week, I’m fully aware that something is wrong. Using a logbook to track symptoms and treat by symptoms is more reliable than blood tests once you are on injections. I want any blood test to show >1500 pg/ml and consider any results in the “normal” to be low as symptoms start coming back. Getting on a stable treatment regime and sticking to it and monitoring symptoms is the best method for repairing nerve damage. Any backsliding causes the repair to be undone very rapidly and the repair is so slow.

in reply to pvanderaa

I understand now. At least you get a week's time space. My friend claims to need B12 every 24 hours. I guess people like this should carry a sort of "dog tag" alerting hospitals to inject B12 in the event of a hospitalization where you are unconscious or in a coma.

Julesboz profile image
Julesboz in reply to

I don’t have PA but if I don’t take a daily B12 tablet I eventually become deficient. I can skip a few days (and frequently do) but after about a week or 10 days I start getting symptoms of deficiency again. There’s no official medical explanation for this, but I have regular blood tests and have proved that not regularly supplementing causes deficiency. Taking B12 daily doesn’t do me any harm and not taking it does. I don’t believe that’s addiction.

in reply to Julesboz

Thanks for your reply. I've read online that some people have a genetic problem where they can't efficiently utilize B12 or convert it or something, so they need continuos high doses. At what age did you start supplementing? How did you find out you needed B12?

Gambit62 profile image
Gambit62Administrator in reply to

the metabolism of B12 is extremely complex at all stages - absorption from food, what happens in the blood and what happens in cells. There are a large number of genes involved and a large number of variants on those genes - many of which are latent - requiring other circumstances to be present before they start acting meaning that life-style could also make a difference. Basically that means that responses can and do vary dramatically from individual to individual.

In someone without an absorption problem stores in the liver are released through bile to be reabsorbed into the blood in the ileum. In someone who has an absorption problem this mechanism does not work very efficiently so stores can't be accessed and used to regulate blood levels in the same way. Liver damage can also cause B12 dumping. This will raise serum B12 levels which can cause a reaction that means that the process that allows B12 to pass from blood to cells much less efficient - leaving the person deficient at the cell level - though raising serum levels higher will resolve this.

Our bodies are designed to absorb nutrients from our food. Supplementing with mega doses can by pass mechanisms that are in place to prevent too much being absorbed in the blood - the saturation that fbirder mentions and could lead to a build up in serum B12 levels as a result which could trigger the reaction that makes transfer of B12 from blood to cells much less efficient, and it also seems to affect the kidney's ability to remove B12 from blood meaning that the B12 stays in the blood longer, leaving the individual trapped in needing to supplement to maintain very high serum B12 levels.

I'm not a medical expert but this is my understanding of how things can fit together.

Personally I wouldn't recommend the use of mega-dose B12 by anyone who doesn't have an absorption problem.

Dealing with a deficiency is a lot more complex - dietary deficiencies can be corrected with use of much lower doses of B12 - but it isn't always clear that the deficiency is dietary and, if symptoms include neurological symptoms then there is a risk of causing permanent nerve damage by delaying treatment. This would normally mean treating with injections which automatically raise serum B12 levels to the point where people could find themselves needing much higher serum B12 levels to function properly. Given that B12 isn't toxic, the need to prevent permanent neurological damage would generally outweigh the risk of condemning people people who don't have absorption problems to needing to maintain very high B12 levels.

Gambit62 profile image
Gambit62Administrator in reply to Gambit62

PS some people can also have genetic variants that affect how efficiently processes in their cells use B12 meaning that they again need much higher B12 levels in their blood to ensure the processes run effeciently.

Fortunately these variations appear to be rare.

in reply to Gambit62

Thanks a lot for this information. This makes so much sense if you think about it. With the exception of PA, for a health condition to require 1000 mcg daily of B12, and B12 being a water soluble vitamin, the odds are you needed the megadoses all your life, and probably would have had neurological damage by the time you were 10 years old. Yet you don't see any children doing B12 on a daily basis. Most of the people I read here about that need daily 1000 mcg of B12 started in their 30s and 40s. So I'm thinking something triggered this dependency, or else you would have had it since childhood. The exception would be pernicious anemia (PA) which can start at any moment in life.

Imagine if you have a stroke and are hospitalized for 3 months (I've known of this happening to someone). I don't know of any hospitals that will supplement their patients in a coma with daily 1000 mcg of B12. By the time you get out of the coma, you will be in a severe state of neurological damage since you skipped your daily B12 for 3 months.

I would still encourage people that can't go 12 hours without 1000 mcg of B12 to try to reduce their supplementation gradually. Maybe they can go back to normal.

Gambit62 profile image
Gambit62Administrator in reply to

if you were in hospital in a coma then you wouldn't be undertaking significant activities and your daily needs for B12 would be lower. The amount you actually need daily is pretty minimal anyway. Liver stores would be more than enough for 3 months. I imagine that care for anyone in a coma would include ensuring that they receive adequate nutrients intravenously anyway.

Nackapan profile image
Nackapan in reply to Gambit62

I've read and re read all the information on your post. I've restarted every other day b12 hydroxocobalamin injections at present six weeks after initial loading doses. I obviously need them at present as I'm slowly improving. I don't like the sound of being saturated though and then your body not coping unless it is all the time. I've been told I've not got PA. So do you actually store any b12 from injections in your liver?

And when no further improvement I'm supposed to jump to to 2 monthly injections. Do you think I should ask to go to weekly then monthly first?

Still don't understand if I haven't PA why my levels were 106 (serum b12) when I eat a very good diet including meat and diary. No other health problems or on any medication ?

Please if you can comment it would help me.

Gambit62 profile image
Gambit62Administrator in reply to Nackapan

PA is not the only absorption problem that is permanent.

If you have had IFA and it came back negative that doesn't rule out PA.

It is impossible to say what the frequency of inhjections should be for anyone with an absorption problem - you need to go by symptoms.

Nackapan profile image
Nackapan in reply to Gambit62

Okay will look into other absorption problems. Yes will go by symptoms . The Nhs rigid regimes make it quite difficult. Glad they have 'allowed' every other day at present. So do you know if the liver can store b12 from injections?

Also interesting for about the body getting used to and then needing to be saturated with b12. Lots to think about

Gambit62 profile image
Gambit62Administrator in reply to Nackapan

if you have an absorption problem then storing B12 in your liver is irrelevant as you won't be able to absorb it when it is released. You will only be able to use the amount that is in your blood from the injection

in reply to Gambit62

Thanks Gambit62. So the liver releases it into the gut for reabsorption?

Gambit62 profile image
Gambit62Administrator in reply to


in reply to Nackapan

Hello Nackapan. I think I'm starting to understand what is going on. I think our bodies start regulating serum levels in response to megadoses. So when you come off a megadose therapy suddenly, you're left with a situation that quickly turns into deficiency. I have proof of this. There is a study which I will link below which shows people in 3 groups taking vitamins. The graph shows that by week number 8, the serum level of vitamins actually drops, suggesting our body starts to block out or expel the vitamin. Once our body is in expelling mode, if you stop supplying the vitamin suddenly, you will experience a deficiency. So a gradual withdrawal would make more sense.

What ever it is, I think correcting the neurological damage comes first. I would rather supplement B12 everyday for the rest of my life and not have symptoms, than be stuck with symptoms that no longer respond to any supplementation.

My advise to you is to continue the injections until all symptoms and problems have been resolved, then gradually start reducing the B12.

Here is the link, scroll down to the middle to look at the graph:

Nackapan profile image
Nackapan in reply to

Thanks I'm understanding more now

Gambit62 profile image
Gambit62Administrator in reply to

serum B12 is not a test that can be used to manage B12 absorption or metabolisation problems. There is no good test for this and all you can do is go by symptoms.

If someone has a functional deficiency (high levels in blood but not enough in their cells) it can take a very long time for B12 levels to reduce to those that were normal before serum B12 levels were raised. In this time your cells will continue to have insufficient B12. If they have any neurological symptoms then these could possibly become permanent in that time.

wedgewood profile image
wedgewood in reply to Nackapan

How can you be certain that you do not have PA? The current test for Intrinsic Factor Antibodies is extreme unreliable . You can heve PA, test several times for it, and the result can be negative . This is a known fact .

Nackapan profile image
Nackapan in reply to wedgewood

I don't know you are right. Wish I did. The Gp just saysI haven't. Everything g else on my last bloods normal Waiting for last week's bloods to come back. I'm carrying on with every other day as a long wayou to go yet. Just grateful some improvement now. Out if bed most of day and simple things like putting washing on the line which wasn't possible until injections re started

pvanderaa profile image
pvanderaa in reply to

Any one over 50, the gut absorption declines as part of the aging process. If she feels she needs a daily B12 dose, she probably does.

Nackapan profile image
Nackapan in reply to pvanderaa

Yes I agree

No, you definitely can't become addicted to it but for a wide number of reasons there are lots of people who need high daily doses every day for life.

Thank you for your post and research - it has provoked some very useful replies and has added to my hunch that the 6 in 2 weeks NHS loading doses are not the best approach. In the Netherlands the loading treatment is one per week and I feel this is better.

In cows, to prevent hypocalcaemia at calving we feed a low calcium diet in the last couple of months before they calve to encourage their system to be more frugal with calcium so they can cope when they start lactating to feed their calves. This emulates the natural levels in grass if they calve in the early spring - which is fine when they do, but some naturally calve in other months and we need to give those more care and restrict their diets to avoid metabolic problems. This also shows that our bodies do adjust to the amount available to them.

I have to inject 1.5mg hydroxocobalamin every day and would slowly die if I didn't. If I use 1mg (1,000 mcg) ampoules I need stupid amounts of sublinguals to just survive. I know others who need 2 jabs a day and will do for life.

I don't have a medic alert bracelet but have thought about it. My phone has a list of my needs in it under ICE and I keep a kit with my jabs and other supplements with me at all times and I tell anyone I am with that if I go to hospital it must go with me. I work on the principle that if I'm in a coma hopefully someone will try to get the ICU staff to treat me - and if they don't I won't be conscious to care if I snuff it - I'll just become another static! If I am conscious I'll get someone to bring me my jabs kit and I'll do my own jabs.

If your colleague needs the B12 she needs it. Please be kind and supportive. It sounds to me that she is taking a big sublingual dose rather than daily injections - or have I misread what you have said? Is this because her body's absorption levels have declined? If so does she need to be encouraged to get injections instead? This could be horribly difficult through the NHS as she is supplementing and therefore her blood levels will be high. If you direct her here we may be able to help her get her own kit to self inject if that would be better.

What we B12d people struggle with more than anything is judgemental people making us feel wrong for trying to help ourselves to stay alive/feel better so if you can break the mould and genuinely listen - and be kind and try to understand - you will be a true friend rather than just another nemesis in a world that is permanently tougher than it is for most people because of this horrible condition - whatever its cause.

Good luck with your health too.

How I agree with every word you have written . An excellent and accurate reply .

Thank you! x

in reply to deniseinmilden

I will direct her here to healthunlocked. The chart that I linked is interesting though as it does show a nonlinear relation between supplementation and serum levels. This would suggest our bodies down regulating B12 infinitely. Of course if you have an absorption problem its impossible to come off of it like Gambit62 explains about due to gut reabsorption failure.

I asked the addiction/dependency question not with any ill intent but rather out of concern. It just so happens that at my place of work I do have another customer who buys tons and tons of Vitamin C. After years of watching him, I finally asked him about it. He says he was hot in the head many years ago and a bullet fragment is still in his brain. He uses Vitamin C to prevent an infection. I've researched this an while Vitamin C will help for infections, it can also cause kidney stones in super high doses.

deniseinmilden profile image
deniseinmilden in reply to

Thank you for your caring attitude - it's good to know you're out there!

Yes always best time be supportive and kind. Wish you well too

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