Let's talk about this annoying subject - B12! Let's gather some material first.

Vitamin B12, Cobolamin

Intestinal flora and vitamin synthesis

Hill MJ, European Cancer Prevention Organization, Lady Sobell Gastrointestinal Unit, Wexham Park Hospital, Slough, Berkshire, UK:

"Unlike most nutrients, absorption of vitamin B₁₂ actually begins in the mouth where small amounts of unbound crystalline B₁₂ can be absorbed through the mucosa membrane."

 "Cobalamin is traditionally administered by intramuscular injections. However, it has recently been shown that the sublingual route is equally effective. In this prospective study of 30 subjects with vitamin B12 deficiency, we found that sublingual and oral administration of 500 µg of cobalamin was equally effective in correcting cobalamin concentrations."

The fact is, B12 can be absorbed even under tong!

Athlete Tim VanOrden on B12:

By Vivian V. Vetrano, Rethinking & Clarifying the Vitamin B12 Issue: 

If we ate 100 grams of green beans, beets, carrots, and peas we would have half of our so-called daily minimum requirement of Vitamin B12 coenzymes providing our digestion and absorption are normal.

A little publicized source of active Vitamin B12 coenzymes is from bacteria in the mouth, around the teeth, in the nasopharynx, around the tonsils and in the tonsilar crypts, in the folds at the base of the tongue, and in the upper bronchial tree. This source alone will supply sufficient quantities of Vitamin B12 coenzymes for the very small requirement of total vegetarians, especially considering that their needs for this vitamin are not as great as for those on conventional diets.

I have studied the Vitamin B12 issue thoroughly, and have learned that biochemists, neutraceutical scientists, and many writers mistakenly use the term Vitamin B12 for cyanocobalamin, THAT IS NOT USABLE BY THE BODY BUT which is in all vitamin B12 supplements. When speaking of Vitamin B12 they are referring to the semisynthetic Vitamin B12 (cyanocobalamin) that initially was contaminated with poisonous cyanide during its chemical extraction from animal tissues. Carbon columns are used during the extraction process and the carbon combines with nitrogen from the medium forming the poisonous cyanocobalamin, that scientists insist on calling Vitamin B12.

The original method used to extract Vitamin B 12 from its sources included heating the medium in a weak acid, the addition of cyanide ion, and exposure to light. In this process the coenzymes were converted to cyanocobalamin, yet this was over looked. (Review of Physiological Chemistry, Harper, Harold A., Lange Medical Publications, New York, 1977, page l81. Also refer to Cobalamin: Biochemistry and Pathophysiology, Wiley. N. and F. Sicuteri, New York, 1972.) MOREOVER, in the manufacture of vitamin supplements, cyanide is added to the medium because the carbon and nitrogen are needed to form large molecules as are found in vitamins; and IN ADDITION they need it to extract the B12 from fermentation liquors and liver homogenates. Carbon is needed in great quantities when making vitamins or any other manufactured vitamin or substance that mimics the natural vitamin that normally contains a lot of carbon.

THE TWO VITAMIN B12 COENZYMES KNOWN TO BE METABOLICALLY ACTIVE IN MAMMALIAN TISSUES ARE 5-deoxyadenosylcobalamin and methylcobalamin (methyl-B12. When extracted in light, these two coenzymes undergo photolysis and are destroyed. Natural B12 is found solely in plants and animals, and that is the only form that can be called “coenzyme B12.”

If an animal or individual is given cyanocobalamin the body removes the cyanide because it is not usable as a coenzyme and it is toxic. Then the cobalt of the former cyanocobalamin can combine with other substances that are not toxic and actually form Vitamin B12 coenzymes that are usable by the body. These normally existing Vitamin B12 coenzymes are labile and break down easily unless inside living tissue.

Potassium in the body can react with the cyanide found in cyanocobalamin – the “Vitamin B 12” – and form toxic potassium cyanide (KCN). Potassium cyanide is a poisonous compound used as a fumigant. This is one reason why the body jettisons the “Vitamin B 12” (i.e., cyanocobalamin) injections so rapidly. Within 24 hours most (about 90%) of the cyanocobalamin in supplements has been eliminated.

The names of cobalamins formed by the body or in a laboratory are: 1. hydroxocobalamin if it combines with a hydroxyl ion (OH), and 2. aquocobalamin, when it combines with water. Cobalamin also combines with anions such as nitrite a form of nitrogen, chloride, and sulfur. These are not usable by the body. The two active coenzymes that can be formed in the body after stripping off the cyanide are 5’deoxyadenosylcobalamin, or adenosylcobalamin for short, and methylcobalamin. The problem is that the cyanide is toxic and makes many people sicker than they were before taking the supplement.

Cyanocobalamin

Cyanocobalamin is in every vitamin B12 supplement known because it is stable and less costly to manufacture. But it is not usable in the body. If the body has sufficient energy it may be able to offload the cyanide and benefit from the useful component. Mainly, what people experience after taking cyanocobalamin supplements is stimulation. The toxic effect of the cyanide triggers a rush of energy as the body works hard to excrete the poison, and this fools people into believing that the supplement has “worked” to heal them. Meanwhile, if their blood tests show an increase in B12, it mainly reflects the amount of the cyanocobalamin in the blood stream. The usable forms are carried into the cells and can’t be discovered by testing the blood as is the current practice. Blood tests are often inaccurate and, as previously stated, in the case of cyanocobalamin supplementation and B12 injections, about 90% of it has been eliminated from the body in 24 hours.

The most common basic cause of a natural cobalamin deficiency is a failure to digest, absorb and utilize the various cobalamins from food and from the intestinal tract as in the case of gastritis or gastroenteritis.

Furthermore, absorption of the natural B12 coenzymes can take place in the mouth, throat, esophagus, bronchial tubes and even in the upper small intestines, as well as all along the intestinal tract. This does not involve the complex enzyme mechanism for absorption (intrinsic factor) in the small intestine as required by cyanocobalamin. The coenzymes are absorbed by diffusion from mucous membranes.

Robin Hur, The Facts About Vitamin B12:

Vitamin B12 is an essential nutrient; it is involved in the production of red blood cells and in the utilization of nervous system-dependent carbohydrates. The inability to absorb B12 leads to so-called "pernicious anemia" in which abnormal red cells are formed, while a lack of B12 in the diet raises the risk of damage to nerves of the spinal cord. Inasmuch as nutritionists report that there is little, if any, of the vitamin in plant foods it behooves strict vegetarians to assure themselves of adequate supplies of B12.

A Mt. Sinai researcher suggests adults need about 0.1 microgram of B12 per day. However, this recommendation is based on observations of individuals taking conventional diets. Normal diets contain gross excesses of fat, protein and refined foods, all of which tend to elevate needs for B12.

Indian researchers found that high-fat intake causes marked B12 deficiency in laboratory animals fed normal amounts of the vitamin; saturated fats, in which beef, eggs and dairy products are extremely high, had an especially severe effect. High protein diets tend to deplete the vitamin in the blood, liver and kidneys of laboratory animals; animal proteins evidently produce more rapid loses than plant proteins. A diet dominated by refined foods more than doubled the B12 needs of baboons. Diets high in animal products, fat and refined carbohydrates lead to conditions in which absorption of B12 is inhibited in humans also.

It appears adults taking low fat, whole food vegan diets should need no more than 0.05 micrograms of B12 daily. The National Research Council recommends adults take 100 times that amount, or 5 micrograms per day. With consistent inconsistency they recommend 1.0 microgram of B12 per day for infants, which is a high multiple of what breast-fed tots get.

It's not altogether clear that nonsmoking vegans need any B12 as such in their diets. The vitamin is normally synthesized by bacteria in the lower regions of the digestive tract and nonsmoking vegans evidently develop the capacity to absorb adequate amounts of their bacterial supplies. British researchers report that only one nonsmoking vegan is known to have suffered from "manifest symptoms and signs" of B12 deficiency. On the other hand, the serum B12 levels of British vegans tend to be very low during their first few years on a vegan regime. And as long as serum levels remain low the possibility of neurological damage persists.

There are several ways in which vegans can protect themselves against declining amounts of B12 in their blood and elsewhere. They could of course take supplements, but supplemental B12 should not be necessary if the diet itself is a sound one. To this end vegans should avoid high levels of fat and protein and avoid tobacco and refined foods. These moves will keep B12 needs down and facilitate synthesis and absorption of the vitamin. As added precautions vegans can include good sources of cobalt and/or B12 itself in their diets.

Each molecule of Vitamin B12 contains a molecule of cobalt so the diet must include a source of cobalt if the intestinal flora are to synthesize the vitamin. Seaweeds are incredibly rich in cobalt: the amount of kelp it takes to flavor a single bowl of salad contains enough cobalt to synthesize a year's supply of B12. And there is growing evidence that raising cobalt intake raises the body's supplies of B12.

The serum B12 levels of rabbits rise when they are fed inorganic cobalt or hay and oats grown in soil containing normal amounts of cobalt. Hamsters fed inorganic cobalt and no B12 had relatively high tissue levels of B12 and seemed to be obtaining entirely adequate amounts of the vitamin.

The Cal-Berkeley researchers who conducted the hamster study reported their result to be "a new finding among the nonruminants." Prior to this finding, though, a Russian researcher had reported that the combination of iron, vitamin C and cobalt had a positive effect on B12 deficiency in humans.

Vegans who want to get their B12 ready-made need look no further than their gardens. An ounce of the roots of leeks, beets, and other vegetables would provide .1 to .3 micrograms of B12 which is more than a day's needs. By eating vegetables right out of the garden one inevitably takes in a little soil and healthy soil contains healthy amounts of B12.

Bacteria

Virginia Messina, MPH, RD, & Mark Messina, PhD, The Vegetarian Way: Total Health for You and Your Family (1996):

All of the Vitamin B12 in the world ultimately comes from bacteria. Neither plants nor animals can synthesize it. But plants can be contaminated with B12 when they come in contact with soil bacteria that produce it. Animal foods are rich in B12 only because animals eat foods that are contaminated with it or because bacteria living in an animal's intestines make it.

Deficiency

Pam Rotella, Vegans and the Vitamin B12 Deficiency Myth:

B12 (also called cobalamin due to its central cobalt atom) is a water-soluble vitamin with a very low recommended daily intake requirement, about 2-3 micrograms per day. That's MICROgrams, not milligrams. In addition to having extremely low intake requirements, Vitamin B12 is stored in the liver, kidneys, and muscle tissue, and most B12 (65-75%) is reabsorbed by the body instead of excreted. A deficiency could take from 5 to 20 years of inadequate intake to develop. The deficiency could be masked by adequate folic acid intake, as the two vitamins work together, but only temporarily. Eventually a B12 deficiency manifests as nerve damage and pernicious anemia, a very serious type of anemia where red blood cells are improperly formed and white blood cell count is low.

The Causes

B12 deficiencies occur primarily when:

1. Something is competing for your B12 (like parasites);
2. Something is destroying your B12 (like cyanide in cigarettes); or
3. Something is preventing the proper absorption of B12 (like inadequate production of intrinsic factor).

Pam Rotella:
It's possible that vegans may be more susceptible to these three factors, as vegans don't consume huge quantities of B12 to counteract such problems (unless they use vitamin supplements). I assume it's also possible that any depletion of intestinal bacteria, for example from lengthy courses of antibiotics, might lead to a drop in B12 production, although I haven't yet found any other author mentioning this as a contributing factor. However, even with these factors present in vegans as well as the population at large, very few vegans develop B12 deficiencies. Most recent books I've found refer to parasites and intrinsic factor (IF) production problems as the common culprits.

Competition (Parasites)

Hulda Clark, the famous research scientist who uses radio resonance in vivo to determine microorganisms involved in cancer, AIDS, and other diseases, finds the parasite Ascaris (a worm-like parasite) is usually involved in cases of pernicious anemia.

Each red blood cell is shaped like a doughnut without the hole. This fits a lot more oxygen, O2, than round balls would. Yet, if there isn't enough vitamin B12, the dimple isn't put into them to make them doughnut shaped. This reduces the body's oxygen supply and the disorder is called "pernicious" anemia. The changed shape of the red blood cells is reflected in a bigger volume called mean cell volume (MCV). The correct volume for red blood cells is about 90 cubic microns. Many elderly persons have a MCV over 100!

I have seen pernicious anemia to be associated with Ascaris infestation. Kill Ascaris on a frequency generator (408 KHz) or zap. The source of Ascaris is usually a pet, owned in the past. Once infected, the tiny worms do not leave your body on their own. The infestation may date back to childhood. What a relief for the bone marrow whose job it is to make red blood cells to have enough vitamin B12 again! What does Ascaris do with your B12? B12 is a beautiful rose colored vitamin. Some worms are actually pink from absorbing your B12! Giving B12 shots is the current clinical treatment for B12 deficiency. Killing Ascaris twice a week by zapping and taking B12 lozenges is a better solution.
-- From The Cure for All Diseases (1995), Hulda Clark, PhD, ND, p. 285

One thing to note about Hulda Clark is that she is NOT an advocate for vegetarianism (although she does concede that meat carries far more parasites and bacteria than vegetable matter). If Clark thought veganism was involved in pernicious anemia, or that people need to eat meat products to avoid it, she would have said so.

Destruction

Another cause of B12 deficiency could be destruction of the Vitamin due to dietary or environmental factors. For example, smoking, high protein diets, alcohol consumption, chlorinated water (disruption by chloroform), and diarrhea may deplete B12.

Gina Shaw, THE VITAMIN B12 ISSUE

A whole lifetime's requirement of B12 add up to a 40 milligram speck of red crystals, about one-seventh the size of an average tablet of aspirin!

Vitamin B12 is excreted in the bile and is effectively reabsorbed. This is known as enterohepatic circulation. The amount of B12 excreted in the bile can vary from 1 to 10ug (micrograms) a day. People on diets low in B12, including vegans and some vegetarians, may be obtaining more B12 from reabsorption than from dietary sources. Reabsorption is the reason it can take over 20 years for a deficiency disease to develop.

In comparison, if B12 deficiency is due to a failure in absorption, it can take only three years for a deficiency disease to occur. Since vitamin B12 is recycled in a healthy body, in principle, internal B12 synthesis could fulfil our needs without any B12 being provided in the diet, but there are other factors to be taken into consideration such as whether there is sufficient cobalt, calcium and protein in our diet to ensure a stable vitamin B2 level and the condition of our intestines.

Among the many controversies surrounding vitamin B12, there is the argument that, although Intrinsic Factor is produced in our stomachs and that our intestines are known to produce vitamin B12, the bacteria is produced too low down in the intestines and cannot be absorbed by our bodies. This argument is still hanging around, however, according to Dr Vetrano it was disproved by research over 20 years ago and is nothing more than an obsolete scientific theory. Indeed, in a 1999 version of 'Human Anatomy and Physiology' by Marieb, it states quite clearly that we do indeed absorb vitamin B12 through our intestines.
B12 synthesis is known to occur naturally in the human small intestine (in the ileum), which is the primary site of B12 absorption. As long as gut bacteria have cobalt and certain other nutrients, they produce vitamin B12.

Dr Michael Klaper argues that vitamin B12 is present in the mouth as well and intestines.

Modern Technology

External B12 coming into the body must be combined with a mucoprotein enzyme named Intrinsic Factor, which is normally present in gastric secretions, to be properly assimilated. If the Intrinsic Factor is impaired or absent, B12 synthesis will not take place, no matter how much is present in the diet. A B12 deficiency can be caused by antibiotics (from the drugs themselves and contained in milk and meat), alcohol (alcohol damages the liver, so drinkers need more B12) and smoking (and all high temp cooked food is smoky) and stress also raises B12 needs). Many nutritional analyses of foodstuffs were carried out such a long time ago, and, as such, have not taken account of more up-to-date technology. According to Dr Vetrano, current books on nutrition in the U.S. now state that there is B12 in any food that contains quantities of the B vitamin complex, but previously they were just not able to assay the amounts. Nowadays, more modern technology has allowed them to discover that there is B12 in those foods rich in the B complex.

Studies

The author does not believe that a vitamin B12 deficiency is more widespread in vegans or vegetarians - this is probably just another marketing lie! In fact, many so-called studies 'showing vegans deficient' have to be carefully studied themselves - many of them do not prove vegans to be deficient at all! In fact, contrary to meat and dairy industry propaganda, meat-eaters are known to be more likely to have a vitamin B12 deficiency - this has been known since 1959!

Having said this, we must bear in mind that many vegetarians and vegans still take antibiotics or consume antibiotic-containing foods such as onions, garlic, strong radishes and other foods rich in mustard oil, which are lethal to intestinal flora. The trouble is that once we have damaged our intestinal flora, it is difficult to correct without proper and knowledgeable healthcare and dietary advice. It is of far greater importance to correct intestinal flora problems than to spend our lives relying on so-called supplements. People who have a physical problem because they think they are not getting enough vitamin B12, are in fact often not digesting, absorbing or assimilating their foods properly because of the condition of their gastrointestinal tract. When their intestines are healed, vitamin B12 can be utilized and produced once again.

Destruction

According to Marieb's 'Human Anatomy and Physiology', vitamin B12 can be destroyed by highly alkaline and highly acid conditions. This assumes that the B12 in meat would be easily destroyed because the hydrochloric acid in our stomachs during the digestion of meat is highly acidic. This may explain why meat-eaters are just as likely to have a B12 deficiency as vegans - even though their diet contains vitamin B12. Also, as mentioned earlier, another problem for meat-eaters is that there are normally antiobiotics in meat plus the fact that many meat-eaters destroy their friendly bacteria in their intestines by constant putrefaction and the putrefactive bacteria naturally present in meat will give the body a hard time.
So, the damaged intestines may not function well enough to enable adequate vitamin B12 levels to be asborbed. Another side to the equation is that low serum B12 levels do not necessarily equate to a B12 deficiency necessarily. Just because there is a low level of B12 in the bloodstream, this does not mean that there is a deficiency in the body as a whole, it may well be being utilised by the living cells (such as the central nervous system). More reliable tests appear to be that of homocysteine levels and Methyl Malonic Acid tests.

Supplements

Dr. John Potter PhD, of Fred Hutchinson Cancer Center, Seattle:

Food's magic is based on thousands of complex interactions of dozens of different phytochemicals which are difficult to recreate in pills. While 190 solid studies prove that fruit and vegetables benefit, supplements have only a smattering of evidence.

Gina Shaw:
On the topic of supplements in general, Douglas Graham, in his book 'Nutrition and Athletic Performance', argues that supplementation has proven to be an inadequate and incomplete method of supplying nutrients as scientists cannot match nature's refined balances. He says that since an estimated ninety per cent of all nutrients are as yet undiscovered, why would we want to start adding nutrients into our diet one at a time rather than eating whole foods? Most nutrients are known to interact symbiotically with at least eight other nutrients and considering this, the odds of healthfully supplying any nutrients in its necessary component package becomes 'infinitesimally minute'. More to the point he adds, 'there has never been a successful attempt to keep an animal or human healthy, or even alive, on a diet composed strictly of nutritional supplements'. So I would say that a reliance on supplements, without getting to the root of the problem isn't ideal.

Organic

Dan Reeter, at Bio-Systems Laboratories in Colorado is creating one of the world's most comprehensive computer facilities for soil biology testing. He says that, from his extensive tests, plants grown in organically-managed soil make significantly higher levels of usable vitamin B12. It has also been reported that vitamin B12 is present in wild fruits and wild and home-grown plant foods.

Animal Products

The author contends that animal and dairy produce is a poor source of Vitamin B12 since they are normally cooked and thereore the vitamin is contained in nutrient-deranged foodstuffs which will inevitably destroy the usability of the vitamin. Studies show that those following a typical animal-based diet require more vitamin B12 than those who do not. This is because the typical diet leads to digestive atrophy. Because B12 is peptide-bound in animal products and must be enzymatically cleaved from the peptide bonds to be absorbed, a weakened gastric acid and gastric enzyme secretions (due to a cooked food diet) causes an inability to efficiently extract vitamin B12 from external food. Nevertheless, raw food vegans can actually get more B12 by reabsorption from bile than they do from external food.

 Wild Plant Foods

Wolfe argues that the natural soil microbes and bacteria found on wild plant foods and unwashed garden plants are typically adequate to supply our B12 requirements. The natural microbes in the soil need to be duplicated and to colonise in our digestive tract, without fermentation or putrefaction.

I would also suggest that just because a wild fruit or organic plant food contains only a small amount, this does not mean it is deficient. It may just be because we only need a small amount anyhow. The pill pushers are quick to say that our soil is deficient, but according to Diamond and others, if a seed does not receive the elements it needs IT WILL NOT GROW (OR WILL GROW POORLY - author). Also, plants obtain nutrients from other sources in greater amounts: the sun, water and the air.

Lifestyle

Another point worth considering is that vitamin B12 Recommended Daily Allowances (RDA's) are based upon the average cooked food (meat and two veg), smoking, drinking person. Commercial interests have indeed grossly exaggerated our needs for many nutrients. These studies tell us nothing of the requirements for a healthy vegetarian. It is very difficult to determine precise individual needs of any vitamin or nutrient, and an overload of any vitamin or other nutrient creates an unnecessary burden on our vital domain. Factors such as rate of metabolism, stress, etc. can determine our differing and often changing needs.

 Requirements

Dr Victor Herbert reported in the American Journal of Clinical Nutrition (1998, Volume 48) that only 0.00000035 ounces (1 microgram) of vitamin B12 is required per day. These minimum vitamin requirements may be inadequate to explain the needs of a healthy raw food vegan, for example, who may require less B12 due to an improved gastric ability and a high ability to recycle vitamin B12. (Cooking destroys microbes and a highly sterilised, cooked vegan diet may not provide the intestines with enough good quality flora). Absorption rates of B12 are inevitably higher in healthy individuals than in unhealthy individuals. Studies, based on healthy Indian vegetarian villagers, showed that none of them exhibited symptoms of B12 deficiency, despite levels of .3-.5 micrograms of B12.

 Absorbtion

I believe that Vitamin B12 deficiency is typically caused by lack of absorption in the intestinal tract rather than a lack of this vitamin in the diet.
Annie and Dr David Jubb argue that people have lived in such a sterile, antiseptic environment for so long that these necessary symbiotic organisms have been less than present in our diet. They argue that by ingesting soil-born organisms you can maintain an enormous reservoir of uncoded antibodies ready to transform specific pathogens, the way nature intended - by eating a little dirt! If a person is healthy and on a healthy vegan, high-percentage raw food diet and does not habitually over-eat, wrongly combine their foods and abuse their bodies generally, and is able to obtain quality produce and utilise fasting quite regularly I would suggest that it is unlikely that they will develop B12 deficiency symptoms providing their intestinal flora was not previously deranged.

Factors

Vitamin B12 deficiency is usually symptomatic of a larger problem i.e. poor intestinal flora, poor absorption, gastric disorders , etc. and can also be attrributed to a lack of sunlight. There are indeed many factors involved here since adequate B12 levels, as mentioned, are dependent upon sufficient calcium, vitamin B12, zinc, cobalt, protein, etc.

Linus Pauling Institute, Micronutrient Research for Optimum Health:

Food-bound vitamin B₁₂ malabsorption is defined as an impaired ability to absorb food or protein-bound vitamin B₁₂, although the free form is fully absorbable. In the elderly, food-bound vitamin B₁₂ malabsorption is thought to result mainly from atrophic gastritis, a chronic inflammation of the lining of the stomach that ultimately results in the loss of glands in the stomach (atrophy) and decreased stomach acid production. Because stomach acid is required for the release of vitamin B₁₂ from the proteins in food, vitamin B₁₂ absorption is diminished. Decreased stomach acid production also provides an environment conducive to the overgrowth of anaerobic bacteria in the stomach, which further interferes with vitamin B₁₂ absorption.

And more general information from the same source:

Vitamin B₁₂ has the largest and most complex chemical structure of all the vitamins. It is unique among vitamins in that it contains a metal ion, cobalt. For this reason cobalamin is the term used to refer to compounds having vitamin B₁₂ activity. Methylcobalamin and 5-deoxyadenosyl cobalamin are the forms of vitamin B₁₂ used in the human body. The form of cobalamin used in most supplements, cyanocobalamin, is readily converted to 5-deoxyadenosyl and methylcobalamin in the body. In mammals, cobalamin is a cofactor for only two enzymes, methionine synthase and L-methylmalonyl-CoA mutase.

Function

Cofactor for methionine synthase

Methylcobalamin is required for the function of the folate-dependent enzyme, methionine synthase. This enzyme is required for the synthesis of the amino acid, methionine, from homocysteine. Methionine in turn is required for the synthesis of S-adenosylmethionine, a methyl group donor used in many biological methylation reactions, including the methylation of a number of sites within DNA and RNA. Methylation of DNA may be important in cancer prevention. Inadequate function of methionine synthase can lead to an accumulation of homocysteine, which has been associated with increased risk of cardiovascular diseases (diagram).

Cofactor for L-methylmalonyl-CoA mutase

5-Deoxyadenosylcobalamin is required by the enzyme that catalyzes the conversion of L-methylmalonyl-CoA to succinyl-CoA. This biochemical reaction plays an important role in the production of energy from fats and proteins. Succinyl CoA is also required for the synthesis of hemoglobin, the oxygen carrying pigment in red blood cells.

Deficiency

Vitamin B₁₂ deficiency is estimated to affect 10%-15% of individuals over the age of 60. Absorption of vitamin B₁₂ from food requires normal function of the stomach, pancreas, and small intestine. Stomach acid and enzymes free vitamin B₁₂ from food, allowing it to bind to other proteins called R proteins. In the alkaline environment of the small intestine, R proteins are degraded by pancreatic enzymes, freeing vitamin B₁₂ to bind to intrinsic factor (IF), a protein secreted by specialized cells in the stomach. Receptors on the surface of the small intestine take up the IF-B₁₂ complex only in the presence of calcium, which is supplied by the pancreas. Vitamin B₁₂ can also be absorbed by passive diffusion, but this process is very inefficient—only about 1% absorption of the vitamin B₁₂ dose is absorbed passively.

Causes of vitamin B₁₂ deficiency

The most common causes of vitamin B₁₂ deficiency are:

• an autoimmune condition known as pernicious anemia
• food-bound vitamin B₁₂ malabsorption. Although both causes become more common with increasing age, they are separate conditions.

Pernicious anemia

Pernicious anemia has been estimated to be present in approximately 2% of individuals over 60. Although anemia is often a symptom, the condition is actually the end stage of an autoimmune inflammation of the stomach, resulting in destruction of stomach cells by one's own antibodies. Progressive destruction of the cells that line the stomach causes decreased secretion of acid and enzymes required to release food-bound vitamin B₁₂. Antibodies to intrinsic factor (IF) bind to IF preventing formation of the IF-B₁₂ complex, further inhibiting vitamin B₁₂ absorption. If the body's vitamin B₁₂ stores are adequate prior to the onset of pernicious anemia, it may take years for symptoms of deficiency to develop. About 20% of the relatives of pernicious anemia patients also have pernicious anemia, suggesting a genetic predisposition. Treatment of pernicious anemia generally requires injections of vitamin B₁₂ to bypass intestinal absorption. High-dose oral supplementation is another treatment option, because consuming 1,000 mcg (1 mg)/day of vitamin B₁₂ orally should result in the absorption of about 10 mcg/day (1% of dose) by passive diffusion. In fact, high-dose oral therapy is considered to be as effective as intramuscular injection.

Food-bound vitamin B₁₂ malabsorption

Food-bound vitamin B₁₂ malabsorption is defined as an impaired ability to absorb food or protein-bound vitamin B₁₂, although the free form is fully absorbable. In the elderly, food-bound vitamin B₁₂ malabsorption is thought to result mainly from atrophic gastritis, a chronic inflammation of the lining of the stomach that ultimately results in the loss of glands in the stomach (atrophy) and decreased stomach acid production. Because stomach acid is required for the release of vitamin B₁₂ from the proteins in food, vitamin B₁₂ absorption is diminished. Decreased stomach acid production also provides an environment conducive to the overgrowth of anaerobic bacteria in the stomach, which further interferes with vitamin B₁₂ absorption. Because vitamin B₁₂ in supplements is not bound to protein, and because intrinsic factor (IF) is still available, the absorption of supplemental vitamin B₁₂ is not reduced as it is in pernicious anemia. Thus, individuals with food-bound vitamin B₁₂ malabsorption do not have an increased requirement for vitamin B₁₂; they simply need it in the crystalline form found in fortified foods and dietary supplements.

Atrophic gastritis

Atrophic gastritis is thought to affect 10%-30% of people over 60 years of age, and the condition is frequently associated with infection by the bacteria, Heliobacter pylori. H. pylori infection induces chronic inflammation of the stomach, which may progress to peptic ulcer disease, atrophic gastritis, and/or gastric cancer in some individuals. The relationship of H. pylori infection to atrophic gastritis, gastric cancer, and vitamin B₁₂ deficiency is presently an area of active research.

Other causes of vitamin B₁₂ deficiency

Other causes of vitamin B₁₂ deficiency include surgical resection of the stomach or portions of the small intestine where receptors for the IF-B₁₂ complex are located. Conditions affecting the small intestine, such as malabsorption syndromes (celiac disease and tropical sprue), may also result in vitamin B₁₂ deficiency. Because the pancreas provides critical enzymes as well as calcium required for vitamin B₁₂ absorption, pancreatic insufficiency may contribute to B₁₂ deficiency. Since vitamin B₁₂ is found only in foods of animal origin, a strict vegetarian (vegan) diet has resulted in cases of vitamin B₁₂ deficiency. Alcoholics may experience reduced intestinal absorption of vitamin B₁₂. Individuals with acquired immunodeficiency syndrome (AIDS) appear to be at increased risk of deficiency, possibly related to a failure of the IF-B₁₂ receptor to take up the IF-B₁₂ complex. Long-term use of acid-reducing drugs has also been implicated in vitamin B₁₂ deficiency.

Symptoms of vitamin B₁₂ deficiency

Megaloblastic anemia

Diminished activity of methionine synthase in vitamin B₁₂ deficiency inhibits the regeneration of tetrahydrofolate (THF) and traps folate in a form that is not usable by the body, resulting in symptoms of folate deficiency even in the presence of adequate folate levels. Thus, in both folate and vitamin B₁₂ deficiencies, folate is unavailable to participate in DNA synthesis. This impairment of DNA synthesis affects the rapidly dividing cells of the bone marrow earlier than other cells, resulting in the production of large, immature, hemoglobin-poor red blood cells. The resulting anemia is known as megaloblastic anemia and is the symptom for which the disease, pernicious anemia, was named.

Neurologic symptoms

The neurologic symptoms of vitamin B₁₂ deficiency include numbness and tingling of the arms and, more commonly, the legs, difficulty walking, memory loss, disorientation, and dementia with or without mood changes. Although the progression of neurologic complications is generally gradual, such symptoms are not always reversible with treatment of vitamin B₁₂ deficiency, especially if they have been present for a long time. Neurologic complications are not always associated with megaloblastic anemia and are the only clinical symptom of vitamin B₁₂ deficiency in about 25% of cases. Although vitamin B₁₂ deficiency is known to damage the myelin sheath covering cranial, spinal, and peripheral nerves, the biochemical processes leading to neurological damage in B₁₂ deficiency are not well understood.

Gastrointestinal symptoms

Tongue soreness, appetite loss, and constipation have also been associated with vitamin B₁₂ deficiency. The origins of these symptoms are unclear, but they may be related to the stomach inflammation underlying some cases of B₁₂ deficiency, or to the increased vulnerability of rapidly dividing gastrointestinal cells to impaired DNA synthesis.

candidly, this is still a grey area for me. and give that i actually know a vegan that is on a very high dose of anti-psychotic medication because of this issue it's something i'm still very nervous about.

I am not quite getting what you mean. This is a well known fact and it is already stated above. We have bacteria, producing b12 in our micro flora.

We need to care about this flora and give it appropriate food (raw plant matter) to profit from our symbiosis.

What else do you know about that vegan? Does he ate raw? Is he a smoker? Did he checked himself on parasites? Were there family mental health issues present in former generations? Is he b12 deficient and is it a proven cause?

Very interesting.

I like doctor Vetrano point of view.

I think B12 deficiency is but a hoax.

It is an attempt to discourage people to revolt against food industry and gain total freedom.

@Tanya, I think the same! -

It is an attempt to discourage people to revolt against food industry and gain total freedom.

It's a shame in my point of view that the Vegan Society scare people with this deficiencies too - in other words, they say: vegan diet is not natural, it is some artificial way of eating, a choice where you must stay on a pill till the rest of your life! - and does no research on this subject. As all others.

Consolidated food businesses are powerful (especially meat and milk industries with all their money and lobbyists, as well as pharma-corporations) and the fear is the best instrument of propaganda.

Newsgroups: sci.med.nutrition
From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: Vitamin B12 and Vegans
Message-ID: <altar.727054890@sfu.ca>
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Thu, 14 Jan 1993 23:41:30 GMT
Lines: 546

>Michael Traub wrote:
> B12 deficiency is more common in omnivores than in vegans.

>Martin Hulsey replied:
> Do you have a peer-reviewed reference from a bona fide nutrition journal that says this?  I have a couple that say quite the opposite.

I have to agree with Martin in that I've not heard of this before either, but I have seen claims to the opposite.  In a trivial sense, of course more omnivores incur B12 deficiency problems simply because there are more of them.  Of course, this is not what is at issue.  What we need are accurate incidence rates (and
ideally breakdowns of the various causes of B12 deficiency) and this would require very large samples of people.

FACTORS THAT AFFECT DIETARY B12 NEEDS

Of course, maybe we need to qualify which "vegans" are clearly at risk and which one's might "theoretically" be at risk.  First, consider some of the factors that are known to increase one's
need for B12:
     (1). Meat or other animal products and refined carbohydrates (sugars) when used generously may more than double B12 needs.
     (2).  Persons who use drugs, chemical, or beverages which destroy B12 (e.g., tobacco, alcohol, caffeine, etc.)
     (3).  Megadoses of vitamin C may produce B12 deficiency by destroying the cobalamins during transport through the gastrointestinal tract (Hines, 1975).  Quantities more than 1/2 of a gram can destroy 50% to 95% of B12 in the food.
     (4).  Oral contraceptives are used (affects the B12 binders of the blood).
     (5).  egg albumin and egg yolk decreases B12 absorption
     (6) intestinal parasitism (e.g., tapeworms) and explosively growing bacterial floras can effectively compete with the host for the vitamin

Given these factors that do increase need, it is apparent that meat eaters do need more B12, but presumably this is adequately compensated for by the fact that they consume more dietary B12. It is of course possible that the compensation may not be great enough.  Rather than only speculate, however, upon a "theoretical" deficiency, it would be best to have in hand some actual actuarial data documenting from large samples the relative rates of B12 deficiency disease among omnivores as compared to vegans.  So far, I've not seen any such actuarial data compiled. But this is understandable when we keep in mind that B12 deficiency is actually rare and of the cases occurring 95% of those cases are not due to a simple dietary deficiency but rather to physiological absorption/utilization problems.

B12 DEFICIENCY AMONG VEGAN INFANTS AND CHILDREN

There are, however, amply studies (see Chanarin et al., 1985; Dagnelie et al, 1989a; Dagnelie, 1989b) upon some groups of vegans whose young  children and infants are documented to show an higher than expected incidence of the signs and symptoms of B12 deficiency (see references below).  This concern for the children of some fad vegetarians that should be seriously noted. There is enough evidence (see references below) to here warrant concern that some vegan groups do incur a risk of B12 deficiency among their young children.  In particular, vegetarian groups prone to certain "fad" vegetarianism like that of  macrobiotic or crudivore diets, seem to sometimes (again, not consistently) have a higher incidence of B12 deficiencies among their young children.

Why certain vegetarian diets or practices seem to incur this problem is not yet understood.  The heavy use of nori, for instance, could be one explanation.  The problem with algae sources like spirulina or nori is not only that they are low in what is being NOW measured as B12 by newer methods (see Herbert, 1988) but that it may not be a true B12 but possibly contains what has been referred to as noncobalamin analogues of B12 that might actually interfere with the absorption of true B12.  In any case, "B12" from spirulina or nori, if it is true B12, is simply  NOT bioavailable (see Dagnelie, 1991).  Another possible explanation would be the "explosive" growing of bacterial floras that can be stimulated by certain very high fiber diets (which would characterized the extreme macrobiotic diets of eating only cereals, particularly rice, which are high in the slowly fermentable fibers that most readily promote microbe proliferation)

In any case, to err on the side of caution, certainly lactating vegetarian women and young vegan children should certainly take some supplements.  The Nutrition Standing Committee of the British Paediatric Assoc recommended in its special report on vegetarian weaning (ARCHIVES OF DIS. IN CHILDHOOD, 1988, 63:1286), for instance, recommended B12 supplements at weaning and for breast feeding vegan mothers.

RECOMMENDED AMOUNTS OF B12

Now, before we consider the more controversial question about whether or not adult vegans have an higher incidence of B12 deficiency disease than omnivores, it might be helpful to keep in mind some of what is known about about B12 needs.

Now, the amount of B12 actually needed by the body is incredibly small and the RDA level is of course more than you need, due to considerations for a safety margin but also because of the measurement problem for small amounts of B12 and the consequent assessment of now much B12 is really necessary for human beings. The National Research Council recommends 3 micrograms (3 millionths of a gram) per day to meet the body's needs.  Victor Herbert, who is probably the leading authority on B12, suggests that 1 microgram would be a better RDA, and he puts the actual requirements of *absorbed* B12 to be round .1 microgram/day (hence, the NRC recommendation may in practice be some to 6 to 30 times greater than our actual requirement).

Absorption of the vitamin also decreases with increased intake. At low levels of intake the mean absorption is 70% (even higher for people with low serum levels of B12), but at high intake levels the absorption rate drops to about 16%.

The fact of the matter is that you need very little and your body can store the stuff for 3 to 5 years.  Hence, you simply don't need to consume B12 every day.  Another point maybe to keep in mind is that researchers really don't know how much low levels of B12 is in our foodstuffs since their is not yet a sensitive enough  assay for trace amounts of B12.

The main rout of loss of bodily B12 in the bile, while most of the bile is effectively reabsorbed (more than 90%), some is not thereby making for a loss of B12 (about .1 microgram/day). Because vegans generally eat less fat and no cholesterol, their production of bile is less and it is therefore likely that their need for B12 replacement would also be less.

VEGAN  SOURCES OF B12

It is true that cultured sources may have little or no B12, but this depends on the culturing process.  Nutritional yeast, for instance, if cultured under controlled conditions so stringently that no bacteria is allowed to grow along with the yeast, then indeed there will be no B12, since the only source in nature is from bacteria  (incidentally, I have been told that the gene for B12 from bacteria could theoretically be cloned onto nutritional yeast so that we could then not only a tasty yeast but one with more than enough B12).  Some nutritional yeasts, may use a B12 rich feed for the yeast, in which case the yeast would then be a good source of B12.

It has been reported that B12 is to be found on the roots and stems of tomatoes, cabbage, celery, kale, broccoli, and leeks. Victor Herbert, however, found that "well washed" plant foods contain no B12 except for trace amounts in some rhibozium-bacteria-containing root nodules.

Some recent dietary intake studies of vegans showed them to be consuming, (including B12 from fortified foods like certain soya milks and margarines) an average intake of 1.2 -1.8 micrograms (Carlson et al., 1985; Sanders et al., 1987; Rana et. al.).  In a Swedish study where fortified foods were not used, the average intake of .35 micrograms was recorded (Abdulla et al., 1981). Gill Langely (1988), in his fine survey of the research on vegan nutrition, reports a study indicating British vegan pre-school children had a mean intake of 280% of the British RDA (but 5 did have intakes less than the recommended intake (Sanders, 1981). An U.S. vegan community that used supplemented soya milk and yeast, had mean intakes of 15 micrograms or about 660% of US RDA for children.  In none of the above groups were any clinical signs of deficiency found.

Maybe a more important consideration than what is to be found in our foods is that much vitamin B12 is actually produced by the body itself.  Bacterial flora in the gut, but also bacterial growth in the mouth, around the teeth and gums, in the nasopharynx, around the tonsils and tonsillar cypts (another reason not to remove tonsils if possible), in the folds at the base of the tongue and even in the upper bronchial tree can produce B12.

It is known that the B12 is produced in huge amounts in the colon (5.0 micrograms/day), though it doesn't seem that it can be absorbed through the walls of the colon.  The small intestine, however, can absorb B12 and indeed some B12 producing bacteria is to be found there.  It is possible that enough intrinsic factor enters the small intestine still sufficiently active to bond with B12 for absorption. It is also possible that vegan physiology enables a more ready absorption (or lower need?), than theoretically expected.  Who knows?  What we do know that people's ability to absorb many nutrients increases as one's need for those nutrients increases.  For example:

     ". . . vegetarians appear to "undergo physiological adaptation enabling them to make somewhat better utilization of iron than would be expected from iron bioavailability studies involving the feeding of vegetarian diets to omnivores or involving the testing of particular components characteristic of vegetarian diets with omnivore subjects." (from Kies & McEndree "Vegetarianism and the bioavailability of iron" in Kies (ed.) NUTRITIONAL BIOAVAILABILITY OF IRON, 1982).

Hence, we must exert some caution in extrapolating the nutritional needs and adaptive capacities of omnivores to that of vegans.  Better, therefore, to look at the DIRECT evidence of vegan health or deficiency.

ARE ADULT VEGANS AT A GREATER RISK OF B12 DEFICIENCY?

Vegetarians who are not vegans but still consume milk products and eggs, probably not need to worry about B12 deficiencies.

Indeed, it is not evident that sensible adult vegans actually suffer from a greater incidence of B12 deficiency than do omnivores.  If one eats a variety of food products, consumes fresh vegetables and is not on antibiotics, then the B12 being produced by bacteria in the gut and the trace amounts from foods may well be sufficient.  The direct evidence for this comes from those studies that have actually tested vegans to see if B12 deficiencies turn up.  In general, the results uniformly indicate that even in the case of those vegans who for decades have not taken any supplements they still appear to have adequate B12 levels.  While the serum levels of B12 tend to be lower than that of an omnivorous control group, hematologic  evidence of vitamin B12 deficiency is not present.

As Gill Langely reports:
    Accepted normal serum levels fall within a wide range -- from
    100-900 pg/ml.  Values below 80pg/ml suggest a possible
    deficiency of B12 while between 80 and 140pg/ml there may or
    may not be symptoms of deficiency.  LOWER THAN NORMAL SERUM
    LEVELS OF THE VITAMIN ARE NOT, OF THEMSELVES, INDICATIVE OF A
    DEFICIENCY.  As already mentioned, vegans of up to 20 years
    standing with no obvious source of the vitamin in their diets
    only very rarely have clinical symptoms of deficiency.
    Although their serum level of B12 does fall over a number of
    years it often stabilizes at about 100pg/ml.  Vegans who take
    supplements or fortified foods generally have higher serum
    levels of the vitamin, while VEGAN MACROBIOTICS OR SMOKERS
    MAY BE PREDISPOSED TO B12 DEFICIENCY.

    Consequently, surveys of vegans document a wide variation of
    serum levels of B12.  On report (Ellis, 1967) mentions values
    between 30 and 650 pg/ml with a mean value (of 20 subjects)
    of 236pg/ml, compared with a range of 120-740pg/ml and a mean
    serum value of 441 pg/ml in matched omniovre control
    subjects.  There was NO CLINICAL EVIDENCE OF B12 DEFICIENCY
    EVEN IN THOSE VEGANS WITH THE LOWEST SERUM LEVELS, although
    one 80-year-old subject who had been a vegan for only 2 years
    had pernicious anemia.  Three vegans who had been on the diet
    for 17 years without taking supplements were healthy, with
    serum B12 levels of 150, 375 and 450pg/ml, and normal amounts
    of haemoglobin in the blood.

    Haematological measurements (Sanders it al, 1978) of 34
    vegans who had been on the diet for between one and 30 years
    revealed a range of serum B12 levels from 94-675pg/ml -- all
    ABOVE the value of 80pg/ml at which deficiency symptoms can
    be expected.  The majority of subjects took B12 tablets or
    food fortified with the vitamin, and those who did had higher
    amounts in their blood.  THE SERUM LEVELS OF THREE SUBJECTS
    WHO HAD BEEN VEGAN FOR 6-13 YEARS (LONG ENOUGH THEORETICALLY
    TO EXHAUST LIVER STORES OF B12) WITH NO OBVIOUS DIETARY
    SOURCE OF B12 WERE ALSO ADEQUATE, at 120-230pg/ml.  All the
    vegans were healthy, none showed symptoms of B12 deficiency
    and all had normal haemoglobin values.  The same report lists
    other surveys of vegans which have failed to show symptoms of
    dietary deficiency of B12.  [emphasis his]

Given what conservative authorities have to say in theory about B12 (especially those that would undertake an analysis of the composition of a vegetarian diet), we should expect to see a greater incidence of B12 deficiency in vegans than in non-vegans, yet there is no such difference as far as I know.

Of course, people will cite some case studies of some unfortunate vegans but such case studies are limited in that we don't have a proper comparison with non-vegans and by now it should be apparent that many other causes besides dietary deficiency can be at fault.  If one looks at these case studies closely, the individuals are often reported as having other deficiencies thereby undermining the very point that such cases might thought to have illustrated in the first place.

What is interesting is that B12 is so extremely rare that even single case studies get published, but the generalizability of such case-studies to the general population of vegans is not to automatically be undertaken.  More evidence than this is needed, especially when the confound of physiological aborption/utilization problems are often not properly ruled out in these case studies.

CAUSE FOR VEGAN PANIC?

Let it again be said, however, that B12 deficiency is "rare" among vegans and that over 95% of deficiency problems are not due to a simple intake inadequacy but are due to an malabsorption problem.  the development of a serious B12 deficiency is not a simple or well understood matter but it is known that absorption and conservation of B12 in the body is more important than how much is to be found in the diet.

known causes of malabsorption are a lack of intrinsic factor (e.g., due to pernicious anemia, destruction of gastric mucosa, etc.), removal or disease of the second portion of the ileum, competition for B12 by microorganisms or intestinal parasites, toxic substances, etc.

beside malabsorption, there are also possible problems (see herbert, 1973) in utilization (e.g., enzyme deficiencies, liver or kidney disease, etc), increase loss (e.g., renal disease) or for an increase requirement (e.g., hyperthyroidism, lactose intolerance).

still, if one has an absorption, loss, or increase need problem, then presumably when little B12 is available in the diet then still less is going to be assimilated.  now, what can vegans do to prevent a B12 deficiency?

HOW VEGANS MIGHT INCREASE

THEIR B12 INTAKES

Fresh garden pricked vegetables, particularly root vegetables, that are not overly scrubbed cleaned or pealed will have some b12 on their surface.  Boiling such vegetables and then throwing out the water would make for a loss of this B12.

Since B12 is predominantly produced by bacteria (no animal produces its own), then foods grown in soils where the bacteria flora is rich would presumable have more B12 on their surface. Hence, organically grown foods will probably be richer in B12.

There is now some recent evidence (Combs, 1991) that some peas and bean actually produce their own B12.  It was previously thought that the only source in nature was bacteria.  This would suggest that such peas and beans would have their B12 throughout rather than just on the surface.  Still, this probably will not suffice as a single plant source to provide sufficient B12.

A simply but useful recommendation is to chew one's food properly and leave plenty of time between meals helps absorption.  The r-binders in saliva help to hold onto the B12 in the food until it reaches the small intestine where it absorbed (Fleming, 1978).

TAKING SUPPLEMENTS.

Multivitamin preparations containing B12 is probably not a good idea.  Besides consuming so-called vitamin "d" which most people do not need and which has been implicated in helping to cause arteriosclerosis and osteoporosis, these preparations contain breakdown products of B12 that can actually have an anti-B12 effect.  Hence, multivitamins may contribute to the very deficiency that they were supposed to correct.  Victor herbert (1962), the leading authority on B12, reported that all of the 10 multivitamin-mineral products that he tested showed anti-B12 breakdown products.  Tests for B12 in the blood unfortunately cannot discriminate between the true vitamin B12 and its breakdown products.

For healthy adult vegans I do think we should be careful about recommending routine B12 supplements.  Even though complete absorption is not likely, the dosages are probably still too high (1200 mcg).  There is some case studies and experimental evidence that an excessive B12 consumption encourages cell division in general and certain tumor cells in particular (bergevin et al., 1976; chauvergne, 1970).

In general, use of B12 supplements should be certainly be considered by pregnant and lactating women, young infants and children, the elderly and vegans not in good health or who still smoke.  Serum levels of B12 are lower for smokers than non-smokers (this may be an effect of the cyanide content of tobacco smoke, which the body attempts to detoxify by a means that unfortunately uses up the stores of B12).

Non-smoking, healthy adult vegans who eat sensibly, are not on medications (e.g., antibiotics) and who do not daily drink alcohol probably do not need to take supplements.  If such vegans are going to take supplements, then they should probably not take them on regular basis since the doses are too high.

Individuals even on conventional diets (diets high in fat and animal protein which increase the need for B12) still only need about 1 mcg per day according to Victor Herbert (recent revision of RDA recommendations has lowered the amount from 3 mcg/day to 2 mcg/day).  Maybe half of a typical 1000 mcg pill about once month would be more than sufficient.  Finally, vegans and non-vegans should make sure that their B12 supplements are derived from bacteria cultures and do not contain spirulina or nori.

If one has been a vegan for a many years, it might be a good idea to have one's serum B12 levels checked.  The normal range is about 150-750 pg/ml according to the merck manual.  Others put it
at 100-900 pg/ml.  There is no exact cutoff.  Vegans, of course, will have levels at the low end but this by itself is not a cause for alarm.  After all, the "normal" range is based upon research from an omnivorous population and vegans do have a lower need for B12 and are more efficient at preservation of extant stores. indeed, it could be argued that the "true normal" range might well closer to that of vegans.  The "ideal" physiological functioning has yet to be determined, but we do know that almost all investigators reporting on vegans report them as being above average in health and more active.

FINAL WORD:

Look, I don't wish to deter any adult vegans from taking B12 supplements.  They certainly can't do any harm and one doesn't have to take them that often.  Better to err, even if it is needless error, on the side of caution.  Also, there are now plenty of B-12 fortified foods.

                                              Ted


REFERENCES 1: General

REFERENCES 2:  Group comparison studies involving adult
vegetarians.

Aphrodite, posted March 05, 2004 11:38 AM

It is possible to develop a B-12 deficiency if your diet and lifestyle are not optimized as much as possible, whether you are a vegan, a vegetarian, or a meat eater. B-12 deficiency is in no way vegan specific.

1) It's impossible to cause a B12 deficiency in animals (primate especially) , even when they're fed for several years in a purified diet without B12 .

2) It's possible to lower the level of B12 in chimps and other animals fed in a purified diet without B12 sources when they're injected with ampicillin and other antibiotics.

3) Studied vegetarian men have more haemoglobin than meat eaters, and vegan had even more than vegetarian as they had lower values for erythrocyte and higher values for corpuscular volume.

4) No serious study in medicine literatures showed that there were B12 deficiency in non-smoker that has been vegan for more than 15 years.

5) No serious scientific studies in medicine literature showed that vegan children had lower vitamin B12 (while the wrong misleading conclusions showed this).

6) All the vegan has higher erythrocyte folate concentration and normal vitamin B12 level

7) The non supplementing vegan showed no macrocytosis or microcytosis, no poly-segmented neutrophils and the level was 180 ng/l were deficiency is seen only under 85 ng/l

The time studied people had been on the vegan diet range from sever years to 35 years.

9) Ten vegan subjects that showed normal or higher level of B12 had been breast fed by vegan mothers.

10) The B12 level of those taking B12 supplements was not much more higher than those that has never taking supplements (321M + 60SE ng/l > 253M + 19SE ng/l)

10b) They failed to find any clinical or haematological evidence of vitamin BI2 deficiency in their studies
none of the vegan peopl studied had vitamin B12 deficient . The studies found no lack of B12 in vegans.
The studies founf no deficiency of B12 in vegans = 80 ng/dl after 5 years of monitoring.

11) There have been few cases in which B12 deficiency in a vegan caused damage to the nerves and spinal cords and they were showed to be due to gastro-enteritis and other pathological conditions, some meat eater relatives showed the same problem and the same low B12 level.

12) Gastric, intestinal, liver organic substances of both primates animals fed for more than three years in a diet without source of vitamin B12 and vegan human had been extracted and showed high content of vitamin B12 and in vitro the extracted organisms showed to manufacture vitamin B12. Both the men and the primate animals had high/normal level of B12.

13) Primates animals fed with a purified diet with B12 supplements showed no differences in folate, and B12 level from chimps fed without B12 sources.

14) Cow and other mammals don't take B12 form the soil. Experiments conducts on these animals showed that their B12 level was still high after three years on a purified diet without B12 sources.
Their intestinal compounds showed to contain organisms that in vitro produced B12.

15) Both in man and animals not eating vitamin b12 sources micro-organisms able to produce B12 had been isolated.

16) Those not taking B12 supplements showed more micro-organism concentration able to produce in their stomachs and intestines than those taking B12 supplement.

Albert, M.J et al. - Vitamin B12 synthesis by human small intestinal bacteria"

17) Experiments carried out on vegans showed that B12 manufactured by bacterial flora in the stomach and intestines (not colon) are highly absorbed in the ileum.

18) Anaerobic Ci perfringens produced the highest level of B12

18a) Only 10% of yeast microorganisms produce 1.0 ng/ml of B12.

18b) 49% of anaerobic bacteria produce 10ng/ml of B12.

19) Anaerobic bacteria in the mouth produce high level of B12 also.

20) Cobamides cultures have been isolated from the liver of primates.

21) Specker Radioessay is known to be ineffective when need to individuate the TRUE B12 from ANALOGUE USELESS B12.

22) All the studies that showed that meat, eggs, milk and cheese are high source of absorbable vitamin B12 have been carried out using Specker Radioessay method.

23) Ochromonas malhamensis is the most precise and accurate method to trace B12 in food and individuate the analogue from the human utilisable.

24) Laboratory head Dr Fukuoca and H Barker, found that B12 content of meat, liver, eggs, cheese, milk was 99% less than what SP showed and found zero human utilisable B12 in all these foods once they were tested with Ochromonas malhamensis instead of SP. Ochromonas malhamensis is rarely used because it's not easy to manage and it costs too much, that's why every food composition table of utilisable by man B12 in food is wrong and false.

25) Vegetables and many fruits (even when washed) show to contain B12. Usually plant food have cobamides ATCC 9614 cultures producing this vitamin.

25a) When tested, these food are processed in acid, added cyanide and exposed to heat, doing so all the anaerobic bacteria are destroyed.
That's why we are told that plants food do not contain B12 wile they do contain it.

25b) As G Ruth stated the medium becomes too acid for accurate resulting when testing B12 content of plants food.

26) it's impossible to find B vitamins in isolation. Where there's vitamin B1, there also vitamin B6 and B12. All plants containing vitamin B contain B12 as well.

27) The B12 found on vegetables when proper method of finding are used is not analogue, but utilisable by man.

28) Mt. Sinai showed that when a diet is too high in fat and protein the B12 need is triplicated.

29) It was possible to induce mild vitamin B12 deficiency in primate animals, by raising their fatty acid level over 30%.

Warning: Roy, A.N. ~ Death after an injection of vitamin B12. Journal of the Indian Medical Association. 1961; 36: 262

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. Large doses of vitamin B1 can also destroy vitamin B12, as can the use of oral contraceptives. Lactose intolerance may increase B12 needs.