B12 overdose / megadose?

[1984]

I know! Lucky that I'm moving to Montreal in a couple of months. Hopefully I'll be able to find someone there that can help me out with this.

See what you've done Korn, now you have me all worked up over something I had decided not to get all worked up about!! ;)

[Korn]

:)

From http://tuberose.com/Vitamins.html

Cases of increased cancer production in animals receiving high levels of B12 have been published. A group of French investigators reported a series of cases suggesting that B12 may stimulate multiplication of cancer cells and aggravate the disease. Patients with rheumatoid arthritis present serum B12 levels significantly higher than normal subjects. It is also known to be higher in patients with ulcerative colitis, leukemia and other serious illnesses. Breast-fed infants get only a tiny fraction of a microgram of B12 per day, even if their mothers are on a high intake. Yet, they can build neurological tissue, convert their hemoglobin from F to A type, and do other complex functions dependent on B12. Iron deficiency interferes with absorption of B12.

[Korn]

From http://www.textfiles.com/food/b12.txt:
There is some case studies and experimental evidence
that an excessive B12 consumption encourages cell division in
general and certain tumor cells in particular

Source: Chauvergne, J. (1970). The risk of administering vitamin B12 to cancer patients. SEMAINE DES HOSPITEAUX PARIS 46:2170

[1984]

I have a question for you Korn....how do you get your vitamin B12??

[Korn]

I have written all these posts about B12, and you still haven't figured that out? :)
The answer is: I'm still trying to find out where I get my B12 from. One of the many reasons I'm interested in the real facts about B12 in plants and the B12 analogue issue, is that I know that B12 test results may increase from one year to another, also in vegans who don't take supplements or fortified foods.

And, to stick to the topic of the thread: I know of several people who have had cancer. In my past/naivity I suggested for these people to check their B12 levels and take supplements, after having heard that B12 overdose is never a problem, and that too little B12 was associated with various health risks, including some cancer types. When these people discussed taking B12 supplements with their doctors and their hospitals, they response was much more negative than positive. I'm not saying that we should trust most doctors or most hospitals, but these people seemed to be informed about the possible link between too much B12 and exaggerated/rapid cancer cell growth/division.

I think it's highly questionable that so few of the supplement fanatics almost never inform about this on their sites (there are some reliable sources, however). Secondly, it is said that 4 out of 10 will develop cancer. The numbers are raising. Lots of people have cancer without knowing it. And: like everybody else, I don't know if I ever will get cancer.

Since we all may develop cancer in the future, we should find out what it is in our lifestyle that can prohibit this. Since both some very conservative, 'pill loving' sources like traditional doctors/hospitals AND alternative sources like well informed vegans have made me aware about the potential dangers of too much B12, I make sure I don't get too much or too little B12.

You may have noticed in other posts that I'm a little reluctant about both giving personal advice and tell about what I do myself, simply because I happen to be the admin of this site: people might believe that I know what I'm talking about, and follow my example :D

Too little B12 in a human means that something is wrong with his diet and/or his body, and/or his lifestyle, and/or the environment. There's also a lot of statistics documenting the increased health risk involved with eating meat. Now, how can we explain for example that meat eaters are more likely to get the most common types of cancer?

Is B12 part of it? After all, B12 is about growth and cell division, among other things; it is necessary for the rapid synthesis of DNA during cell division. Cancer = abnormal and uncontrolled cell division.

Do I know if too much B12 can cause cancer? No. Would I be surprised if it will be proven in the future? Not at all.

In case there's any confusion – I encourage people to check their B12 levels and take supplements when/if needed. For those who don't: it's considered safe to take a 'normal' B12 supplement, and for vegans too little B12 is a much more imprtant concern than getting too much of it (unless you are taking megadoses of B12).

[Korn]

We have another thread about cancer, but since B12 is THE nutrient that we know there is more of in meat than in plants, and high meat intake is associated with increased cancer risk, I'm posting a few more links about the meat/cancer link:

From http://www.cancer.org/docroot/NWS/content/NWS_1_1x_Eating_Lots_of_Meat_Can_Increase_Cancer_R isk.asp:
Eating Lots of Meat Can Increase
Cancer Risk

Fruits and Vegetables Good for Stomach and Esophagus
Article date:*2001/12/19

Eating too much meat and not enough fruits and vegetables may increase a person's chances of getting certain esophagus and stomach cancers. In a study published in the journal Cancer Epidemiology, Biomarkers and Prevention (Vol. 10, No. 10: 1055-1062), researchers from several US medical centers and the National Cancer Institute looked at foods that might be related to cancer.


The incidence of four specific types of stomach and esophagus cancers has been increasing in the last few years. In contrast, rates have been stable or even decreased for other types of stomach and espophagus cancers. Most cancer epidemiologists believe that diet plays some role in all four of these cancers.


From http://bmj.bmjjournals.com/cgi/content/full/330/7483/111-a
Evidence grows that eating red meat increases cancer risk

From http://bmj.bmjjournals.com/cgi/content/full/324/7353/1544/f
Eating meat more than 10 times a week almost doubles chances of bowel cancer
Those who ate processed meat more than five times a week were 1.5 times more likely to develop bowel cancer than those eating it no more than once a week.

From http://www.cancerresearchuk.org/aboutcancer/reducingyourrisk/diet
Eating lots of red or processed meat is a risk factor for bowel cancer. There is also some evidence that breast, lung, prostate and pancreatic cancers are linked to a diet high in red or processed meat.
(I know there is some controversy about breast cancer/meat link. Korn).

[1984]

Well Korn, I must say, you have inspired me to look much further into this issue than I was going to. I am very impressed with the amount of research you have put into this pesky little B12. This forum holds a massive amount of information on B12, one of the most extensive resources I have ever come across. Thanks for the help, its about time I looked into this for myself, rather than listen to what everyone else has to say.

[Korn]

This forum holds a massive amount of information on B12, one of the most extensive resources I have ever come across.
There's A LOT more to come...
:)

[Korn]

http://www.mothernature.com/Library/Ency/Index.cfm/Id/2924006 :
Although quite rare, serious allergic reactions to injections of vitamin B12 (sometimes even life-threatening) have been reported.28 29 Whether these reactions are to the vitamin itself, or to preservatives or other substances in the injectable vitamin B12 solution, remains somewhat unclear. Most, but not all, injectable vitamin B12 contains preservatives.

[Korn]

Too little B12 is NOT good. But too much may not be good for you either.

Look at this page: http://www.emedco.com/emed2/resource/msds/msds_view.asp?pd=ch&pf=cjsnw

It says that
THERE IS LIMITED EVIDENCE THAT VITAMIN B12 IS TERATOGENIC IN LABORATORY ANIMALS. UNTIL FURTHER TESTING HAS BEEN DONE, IT SHOUL D BE TREATED AS A POSSIBLE TERATOGEN IN HUMANS.

This text refers to synthetic vitamin B12 from Cabiochem, and says nothing about the amount of B12 that is needed for teratogenic behavior.

(Teratogene: "An agent or substance that may cause physical defects in the developing embryo or fetus when a pregnant female is exposed to that substance.")

Again, vegans are much more likely to get B12 deficiency than to get a B12 overdose, because this is impossible on a vegan diet. But remember that supplements are supplements, and should not be treated like food!

Here's another teratogen list:
http://www.evol.nw.ru/labs/lab38/spirov/hazard/teratogen_lst.html

[Korn]

I also came across B12 in a list of allergen components, under 'cobalt dichloride':
http://www.mekos.dk/page.asp?sideid=13&zcs=27

[Cal]

But remember that supplements are supplements, and should not be treated like food!
That's the way I try to treat them. We aim to eat a good variety of vegan foods, made up of about 75% raw food, in our house and it seems to keep us fit and well. :) We do take a B12 supplement but consider the good fresh food is the most important thing.

[mixtlupus]

I found this site whilst looking to see if I have anything to worry about with the symptoms I am experiencing after a suspected (Hydrocobalamin) B12 overdose...

I can firsly put most peoples minds at rest by saying that if you are taking B12 in tablet form you will certainly not have overdosed, this includes anyone who consumes an entire bottle of industrial strength B12...

The body only absorbs minute amounts of B12 from the food and drink you consume, A glass of milk contains 15% of the B12 RDA. Whilst 100g of Liver contains 3700% of the B12 RDA...

As you see most meat eaters consume at least 10,000% the RDA in any one day, but only a small amount is actually absorbed in to the bloodstream.

Alcohol absorbs B12 from the system, which is why people crave kababs and meaty foods after a night of drinking...

The body is capable of storing 10 years worth of B12 for anyone whi is T-Total


My situation is slightly more complex, I suffer from a B12 deficiency (penicious anemia) due to my diet, I have been a strict Vegan for 17 Years now. For a number of years I have been recieving B12 (Hydrocobalamin) injections direct in to my arm muscles for slow release and absorbsion into the system.

I believe that at the drop in centre the nurse may have stuffed up my Injection, it was not painfull as usual (it's meant to hurt) and 12 hours later i'm experiencing some awkward side effects, which makes me think that the entire 3 months dose went straight into my bloodstream...

Side effects are as follows, Numbness and pins an needles in all my extremities, soar stomach (actually muscle pain), a feeling of being attached to a low voltage current (feels like you have just been scared, the shivering feeling you get afterwards), slightly blurry vision (but only when I change focus), a slightly racing mind (but no energy boost) and a tight chest (whilst i've been writing this post).

If the effects continue till morning I will consult my doctor, but for now I thought i'd let people know they are safe...

Thanks,
Mixtlupus.

[Korn]

I can firsly put most peoples minds at rest by saying that if you are taking B12 in tablet form you will certainly not have overdosed, this includes anyone who consumes an entire bottle of industrial strength B12...
Hi, what sources do you have that back up this? Have you read the earlier posts in this thread?


As you see most meat eaters consume at least 10,000% the RDA in any one day, but only a small amount is actually absorbed in to the bloodstream.

What RDA are you referring to, and where is the info that documents that meat eaters (which not at all should be any reference for healthy living, by the way), consumes 100 times as much? This would mean, for example that if the RDA is 3 mcg, your suggestion would mean that meat eaters consume 300 mcg pr day....



Side effects are as follows, Numbness and pins an needles in all my extremities, soar stomach (actually muscle pain), a feeling of being attached to a low voltage current (feels like you have just been scared, the shivering feeling you get afterwards), slightly blurry vision (but only when I change focus), a slightly racing mind (but no energy boost) and a tight chest (whilst i've been writing this post).

You are experiencing all this and say that it's safe to consumes an entire bottle of industrial strength B12? If I'd experience all that, I'd call a doctor immediately.....!

[mixtlupus]

Hi, what sources do you have that back up this? Have you read the earlier posts in this thread?

It is a fact that most people consume what would be considered an overdodse on a daily basis, please note that he key word is consume.



What RDA are you referring to, and where is the info that documents that meat eaters (which not at all should be any reference for healthy living, by the way), consumes 100 times as much? This would mean, for example that if the RDA is 3 mcg, your suggestion would mean that meat eaters consume 300 mcg pr day....

The RDA as set out by the FDA, B12 levels are still high in a non healthy diet. Most people eat at least 100g of meat per day, not to mention that most foods (eg. cerials) are now fortified... 100g of cornflakes with skimmed milk constitutes 85% of the RDA, all the figures I mentioned are freely available on-line on many sites such as the FDA site...




You are experiencing all this and say that it's safe to consumes an entire bottle of industrial strength B12? If I'd experience all that, I'd call a doctor immediately.....!

Remember their is a big difference between consuming B12 (of which a small amount is absorbed and the rest passed in to your bowel) and having it injected straight into your bloodstream (bypassing the bodys natrual ability to only absorb whats needed), my body is currently burning the excess B12 from my system, I'm feeling much better if not quite hot (In my line of work it's not always possible to get time off which is why i'm waiting till morning), as a long term sufferer of a thyrod desease I've felt much worse...

I've had a deficiency for seven years now, I like to know as much as possible about the issues I may have so much of my knowledge has been through talking with doctors.

[mixtlupus]

Another reason that I have not yet consulted a doctor is that a direct B12 injection is used to clear the system of syanide when someone goes into hospital with syanide poisoning. This is a widely practiced treatment and has no known long term side effects...

[Korn]

Beef is said to contain circa 2 mcg B12 pr 100 g... Burgers and canned beef is said to contain circa 1 mcg B12/100g.
Except for kidney and liver, which most people don't eat that often, B12 levels aren't that high in most animal products:

Oysters 6 =1,02mcg
Egg 1=0,56 mcg
Milk, a cup =0,83mcg
Steak 100g =2,11mcg
Omelette 1=0,43mcg

Not that there's any need to use meat eaters as a reference for what amount of B12 we need to consume, but they only consume a few few mcg B12 pr day.

[mixtlupus]

Beef is said to contain circa 2 mcg B12 pr 100 g... Burgers and canned beef is said to contain circa 1 mcg B12/100g.
Except for kidney and liver, which most people don't eat that often, B12 levels aren't that high in most animal products:

Oysters 6 =1,02mcg
Egg 1=0,56 mcg
Milk, a cup =0,83mcg
Steak 100g =2,11mcg
Omelette 1=0,43mcg


See the following chart http://www.beyondveg.com/tu-j-l/raw-cooked/raw-cooked-3c.shtml

Remember the body has the ability to Store B12 for up to 10 years, which means that levels are very unlikely to become low unless you have an absorbsion problem or have been a strict Vegan for a number of years, most people will eat more liver than they know, I hazzard to say do you know whats in your sausages or beefburger these days... Many foods contain milk solids and other forms of B12 that you wouldnt normally consider being there unless you read the packaging...

B12 is everywhere, if you consider fortified foods alone, not to mention meat, dairy or eggs...

Some B12 fortified foods are:
Bread, Brewers Yeast, Soya Milk, Rice Milk, Cereals, Snack Bars, Energy Drinks, Fruit Juce / Smoothies (some of Asda's fruit jucies contain lactose so watch out), Margarine, Vegetarian Meals (such as Linda Mccartney Meals, again watch out as ALL LM products contain milk in one form or another, before you say its not on the ingredients, it's been there hidden for many years (since Linda passed away) discuised as flavouring, feel free to check this with Hinez (I did)), Yogurts, Micro Biotic Drinks, Many Diet Foods...

Also the RDA is purposefully set high due to the absorbsion rate of B12...

Plants would also contain ample amounts of B12 if it wasnt for modern farming tecniques which kill the micro-bacteria in the soilthat would otherwise allow plants to absorb B12...




http://www.freedomyou.com/nutrition_book/Modern%20Meat.htm
B12 is the largest and most complex of all vitamin molecules. It cannot be synthesized. This vitamin is used by the body in such small quantities that the amount on the head of a pin would prevent deficiency for three years (1 milligram). B12 is so minute, it is measured in billionths of a gram.

B12 is formed through microbacterial action. This occurs in the ground by the bacteria in the soil, bacterial action in the stomachs of cows and pigs, and by bacterial action in the intestine of man.

Normally, B12 is absorbed by plants from the bacterial action in the ground. Sadly, soil bacteria have been destroyed through modern farming. Pesticides leach into the ground, killing the bacteria responsible for creating B12. If B12 is not in the soil, it’s not in your veggies.

What about B12 in the intestine? Meat, the recommended source of B12, ferments and creates toxic by-products which destroy intestinal bacteria. Non-B12-producing harmful bacteria take over. This leaves you totally dependent on the B12 derived from the bacterial action of cows and pigs.

There are very few non-meat sources of B12. Tofu, tempeh and soy sauce are made from fermenting soybeans. The fermentation makes these products a source of B12. However, taking a B complex vitamin supplement is a good insurance policy for vegetarians.

[mixtlupus]

That chart confirms what I just wrote, that 100g beef contains in the neighbourhood of 2mcg B12. I'm surprised that they got this right, because beyondveg must be worst possible source of information that exist about veganism and nutrition.
I can se that your not actually intrested in listening to anything that people say and put most your efforts into poking holes in everything that is said...

the sources quoted were just a few examples, not to be taken as gospel, theywere easy to find and to the most accurate...

Before you poke any holes in the next link that should contain most the info on B12 that you could wish for (oh and do look at the charts), I should mention that this is OFFICIAL ODS material sanctioned by the government and reviewed by 4 doctors:
http://ods.od.nih.gov/factsheets/vitaminb12.asp

Please note the section that states and I quote:
As a general rule, most individuals who develop a vitamin B12 deficiency have an underlying stomach or intestinal disorder that limits the absorption of vitamin B12

[Korn]

I can se that your not actually intrested in listening to anything that people say and put most your efforts into poking holes in everything that is said...

Look at this: what would happen if people who visit this board would read what you wrote and think that 1) I'm a meat eater, so I have been eating 10,000% of the RDA for B12 for all my life, and 2) This will be stored in the body for 10 years....? They would think that 'If I go vegan, I don't need to monitor my B12 levels for 10 years'. There's a fair chance that they will develop B12 deficiency (you did!). When your information is as wrong, it can lead to serious trouble, and I just don't want to look at that without trying to correct it...


the sources quoted were just a few examples
The point is that the sources you referred to was not at all backing up your statements! I'm not interested in proving that I'm right and that you're wrong, but more and more people look to this forum for info, and some of these might be meat eaters who want to go vegan because they don't feel well on their current diet. Maybe one of the main reasons they don't feel well, is that they are among the 39% of meat eaters that are low in B12.


Before you poke any holes in the next link that should contain most the info on B12 that you could wish for (oh and do look at the charts), I should mention that this is OFFICIAL ODS material sanctioned by the government and reviewed by 4 doctors
Have a look again. It does not back up your statements regarding meat eaters who eat 10,000 % of the RDA pr day, neither does it say that vegans (or meat eaters) are safe for 10 years without supplements due to the stored B12.

What it does say, like a number of other sources does, is that 'The Institute of Medicine of the National Academy of Sciences did not establish a Tolerable Upper Intake Level for this vitamin because Vitamin B12 has a very low potential for toxicity. The Institute of Medicine states that "no adverse effects have been associated with excess vitamin B12 intake from food and supplements in healthy individuals' - which is a main reason this thread has been started, because as you can see (if you have read the other posts in this thread), there is disagreement about this.

If a meat eater should be able to consume 10,000% of the RDA for B12, he would have an have extreme diet, and/or take a lot of supplements. To compare vegans with meat eaters, but use meat eaters who take a lot of extra B12 as a reference, doesn't really make sense. And again, since meat eaters are known for their high cancer risk among many other things, why would we use them as a reference for something that's not risky?



As a general rule, most individuals who develop a vitamin B12 deficiency have an underlying stomach or intestinal disorder that limits the absorption of vitamin B12 This has been a pretty common way of explaining low B12 levels among meat eaters for many years, especially by people who are not aware of all the B12-killers out there. Whether it's right or wrong isn't of much relevance for vegans, because there's no scientific evidence suggesting that the most common cause of B12 deficiency among vegans is underlying stomach or intestinal disorders.

Dear mixtlupus, I admire your stubbornness, but since you already have told us that you both suffer from B12 deficiency and from symptoms of a B12 overdose, maybe it's time to double check your sources and viewpoints. Please don't get this wrong, but if you had done that earlier, maybe you wouldn't have had any of the problems you describe. Unfortunately, people who trust your information run the risk of experiencing the same problems. I don't blame you, because there are several sites out there who think along the same lines, and if you get your info from one of these, and don't realize that other books/sites/expert have other conclusions and different advice to offer, you might fall into a trap of trusting that 'new vegans are safe for 10 years' or 'meat eaters are safe' or 'multivitamins are safe' etc. It's too bad that so much of the 'information' out there is only scratching the surface, but I think part of the explanation for this is that people keep banging each others heads with various reports they trust (usually the reports they came across first) instead of looking at disagreeing 'experts' who have different conclusions.

Again: I don't want a meat eater who visits our site and who wants to switch to vegan food tomorrow to believe that he's full of B12 or that he is safe for 10 years, because there's a fair chance that he already is low in B12. If he's already low in B12, he stored supplies won't last for 10 years. That's the only reason I try to 'poke holes' in what you write... nothing personal! :) There's also a fair reason that he has more B12 in his body than he needs - in which case, there's no reason for him to take B12 supplements.

As a last comment to the official information you referred to at http://ods.od.nih.gov/factsheets/vitaminb12.asp, it lacks a lot of important information (for example about drugs that interfere with B12 absorption), it does not discuss B12 analogues (in meat, plants, multivitamins, fortified food and animal products) at all, but here is what it says about the B12 levels in unfortified animal products, not based on RDA or 'DRI' (normally less than 3 mcg), but a 'daily value' which they define as 6 mcg pr day (most others don't use such a high reference):



Mollusks, clam, mixed species, cooked, 3 ounces / 84.1mcg / 1400%
Liver, beef, braised, 1 slice / 47.9 mcg / 780%
Fortified breakfast cereals, (100%) fortified), ¾ cup / 6.0 mcg / 100 %
Trout, rainbow, wild, cooked, 3 ounces / 5.4 mcg / 90%
Salmon, sockeye, cooked, 3 ounces / 4.9 mcg / 80%
Trout, rainbow, farmed, cooked, 3 ounces / 4.2mcg / 50%
Beef, top sirloin, lean, choice, broiled, 3 ounces / 2.4 mcg / 40%
Fast Food, Cheeseburger, regular, double patty & bun, 1 sandwich / 1.9 mcg / 30%
Fast Food, Taco, 1 large / 1.6 mcg / 25%
Fortified breakfast cereals (25% fortified), ¾ cup / 1.5 mcg / 25%
Yogurt, plain, skim, with 13 grams protein per cup, 1 cup / 1.4 mcg / 25%
Haddock, cooked, 3 ounces / 1.2 mcg / 20%
Clams, breaded & fried, ¾ cup / 1.1 mcg / 20%
Tuna, white, canned in water, drained solids, 3 ounces / 1.0 mcg / 15%
Milk, 1 cup / 0.9 mcg / 15%
Pork, cured, ham, lean only, canned, roasted, 3 ounces / 0.6 mcg / 10%
Egg, whole, hard boiled, 1 / 0.6 mcg / 10%
American pasteurized cheese food, 1 ounces / 0.3 mcg / 6%
Chicken, breast, meat only, roasted, ½ breast / 0.3 mcg / 6%


In my opinion, this site both avoids a lot of extremely important B12 information, it contains some errors, but it also presents some of it's material in better ways than many 'vegan experts' do.

[Korn]

Here's some text i have found about cobalt overdose, which may or may not be relevant to this thread:


Cobalt (Co)

Minerals containing cobalt were of value to the early civilizations of Egypt and Mesopotamia for colouring glass deep blue. Cobalt was announced to be an element by Georg Brandt about 1739 (or possibly 1735). He had been trying to demonstrate that the blue colour of glass was because of a new element, cobalt, rather than bismuth, an element often found in the same locations as cobalt. Cobalt was originally named from the German word "kobald" meaning "goblin" or evil spirit.

Cobalt salts in small amounts are essential to many life forms, including humans. It is at the core of a vitamin called vitamin-B12. Grazing animals do not to do well in areas where there is little cobalt in the soil.

Cobalt is a brittle, hard, transition metal with magnetic properties similar to those of iron. Cobalt is present in meteorites. Ore deposits are found in Zaire, Morocco and Canada. Cobalt-60 (60Co) is an artificially produced isotope used as a source of g rays (high energy radiation). Cobalt salts colour glass a beautiful deep blue colour.

Signs of deficiency: Anemia, anorexia, bleeding gums, confusion, dementia, depression, difficulty maintaining balance, headache, nausea, numb and tingling extremities, pale gums, pale lips, pale tongue, poor memory, retarded growth, shortness of breath, sore tongue, weakness in the arms and legs, weight loss, yellow eyes and skin. However, if a normal diet is followed a deficiency is most unlikely.

An excessively high intake of cobalt may damage the heart muscles, and may cause an over-production of red blood cells or damage to the thyroid gland.

Signs of toxicity : Cardiomyopathy, erythrocytosis, polycythemia, enlarged thyroid, diarrhea, fatigue, heart palpitations, numbness, and paleness. Some beers are cobalt-stabilized.

Since cobalt is part of the vitamin B12 molecule, the function of cobalt is interwoven with that of vitamin B12.

If you know more about the link between B12 and cobalt overdose, please let us know....

[Korn]

From http://www.acu-cell.com/nico.html



Some uninformed practitioners believe that there is no overdose possible with Vitamin B12, however 5-10% of the population presents with above-normal levels of Vit B12, so if injections are erroneously given, they can trigger a number of adverse symptoms that may include coronary artery spasms with chest pains, numbness or pain down their right arm, and/or TIA-like symptoms with tingling / numbness on the right side of the face.

There is also a risk of hypokalemia, pulmonary edema, peripheral vascular thrombosis, optic nerve atrophy for someone with Leber's disease, and others. Risks from intranasal use of Vitamin B12 include glossitis, headache, sore throat, rhinitis, and feeling of "pins and needles." Individuals suffering from Mitral Valve Prolapse (MVP) are also vulnerable to experience a worsening, or an acute flare-up of MVP symptoms following a Vitamin B12 shot if not indicated.

Even without having had any Vitamin B12 injections, individuals who run naturally high Vitamin B12 and cobalt levels (which may include patients with mitral valve prolapse), tend to frequently suffer from tachycardia, panic-anxiety attacks, or angina-like chest pains, that may be accompanied by numbness and tingling in the face or extremities.

In contrast to cellular measurements, blood tests for cobalt or Vitamin B12 levels (including the Schilling test) are not only very unreliable, but at times alarmingly wrong, subjecting patients to improper therapy, or routinely misdiagnosing them as Psychiatric Cases , when in fact correcting their abnormal cobalt, Vitamin B12 and nickel status (or ratios) could resolve the problem.

[Haniska]

I have been taking a sublingual methyl- b12 supplement for a few weeks now. I wonder if it is to blame for my painful joints?? It has 16,670 % (1 mg) of the rda! RIDICULOUS yes, but I figured I would try it out and maybe not take any the rest of the year. I also just started taking OMEGA-3-ZEN a few weeks ago as well.. hmmmm. Think I'll give it up for a few days, might have to hide it though, I'm starting to crave them. If indeed that pain is caused by the b-12, is there any way that that could be a good thing? Awakening my nerves or something? (I have crooked joints).

[marika5]

High B12 doses might also cause acne in some people.

I think with the 1000 mcg sublingual b12s maybe the best way to use them is to cut them into fourths and take only 1/4 once per week rather than one every day. At high doses absorption is poor but maybe some people are still getting more than what they need for best health.

My multi has 100 mcg methycobalamin but I try not to take it every day.

--

Cutis. 1991 Aug;48(2):119-20.

Acneiform eruption due to "megadose" vitamins B6 and B12.

* Sherertz EF.

Department of Dermatology, Bowman Gray School of Medicine, Winston-Salem, North Carolina 27103.

Medications and other exogenous factors are known to be capable of exacerbating acne or precipitating acneiform eruptions. This case illustrates an eruption resembling acne rosacea that was temporally associated with daily ingestion of high-dose B vitamin supplement. The eruption failed to respond to the usual treatment regimens for rosacea, but promptly improved when use of the vitamin supplement was discontinued.

PMID: 1834437 [PubMed - indexed for MEDLINE]

[Korn]

Here's some info about problems with using commercial nasal B12 supplements (gel or spray:

http://www.medicinenet.com/cyanocobalamin-nasal/article.htm

GENERIC NAME: CYANOCOBALAMIN - NASAL (SYE-an-oh-koh-BAL-uh-min)
BRAND NAME(S): Nascobal
[...]
USES: This medication is used to treat vitamin B12 shortage. This product should not be used to test vitamin B12 absorption (Schilling test).

HOW TO USE: This medication is usually used once a week in the nose or as directed by your doctor. Use this medicine at least one hour before or after hot food or drink. Learn the proper way to use this from your pharmacist or doctor and follow all instructions carefully. Certain conditions may require lifelong use of this drug. Treatment is usually postponed when nasal congestion, common cold or allergies are present.

SIDE EFFECTS: Headache, nausea, dizziness or nasal congestion may occur. If these persist or worsen, notify your doctor. Though very unlikely to occur, notify your doctor if you develop any of the following: muscle cramps or weakness, leg or arm swelling or pain, tingling of the hands or feet. In the unlikely event you have a serious allergic reaction to this drug, seek medical attention immediately. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.


..or here:

http://www.drugs.com/mtm/B/B_12_Resin.html




B-12 Resin
This page contains drug information on B-12 Resin.
The information provided includes the following:
what is B-12 Resin
the possible side effects of B-12 Resin
what happens if you miss a dose of B-12 Resin
what happens if you overdose with B-12 Resin
the most important information about B-12 Resin
how to use B-12 Resin
other drugs that may affect B-12 Resin
what to avoid while using B-12 Resin
[...]
What are the possible side effects of cyanocobalamin?

• if you experience any of the following serious side effects, stop taking cyanocobalamin and seek emergency medical attention:
• an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
• chest pain or difficulty breathing; or
• unusual warmth, redness, or pain in an arm or leg.
• Other less serious side effects may be more likely to occur. Continue to take cyanocobalamin and talk to your doctor if you experience
• headache;
• upset stomach or diarrhea;
• numbness or tingling;
• fever;
• dizziness;
• felling of swelling of entire body; or
• itching or rash.
• Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.


So, too much of this stuff through the nose isn't good. But - talking about the nose - that shouldn't be a problem with getting B12 (cobalamin) from pollen through inhaling fresh, air or by using (eating) pollen products based on pollen (http://www.veganforum.com/forums/showthread.php?p=230621) not collected by bees...