B12 and B12 analogues in multivitamins, animal foods and spirulina

[tricia]

[Edit: This post is a collection of earlier posts on B12 and spirulina from "Veganforum 1".]

Korn Posted: Mar 7 2004, 11:21 PM


From http://216.239.59.104/search?q=cache:6gaQt...&hl=en&ie=UTF-8 :

"Assays of vitamin B-12 in Spirulina Pacifica using the standard US Pharmacopeia (USP) method to measure total corrinoids reveals an average activity of about 7 micrograms per 3 grams of Spirulina (one serving size). Using the O. malhamensis assay in parallel to specifically measure human-active cobalamins the assay exhibits an average activity of 2.5 micrograms per 3 grams of Spirulina. These figures demonstrate that about 36% of the total corrinoid vitamin B-12 activity in Spirulina is human active. An additional non-dietary source of low amounts of absorbable vitamin B-12 may be obtained from bacteria in the small intestine of humans (Albert, 1980). Spirulina is not an animal source, but rather a vegetarian source of cobalamin B-12 amongst many other nutrients and antioxidant carotenoids. Normal healthy vegetarians should be able to attain sufficient levels of cobalamin to fulfill their requirements with a few serving sizes daily. As before, those with metabolic defects or absorption difficulties should always consult medical advice and monitor their condition closely".

I don't know much about spirulina myself, but I wonder if anyone can comment on the above quote? I've seen a lot of conflicting info on 'true' vs 'analogue' B12 in spirulina...



globesetter Posted: Mar 8 2004, 10:10 AM


I have also read conflicting info about spirulina, and so am no thoroughly confused.

Based on the articles you«ve been quoting on the site, Korn, it seems that spirulina is a better source of B12 than multivitamins ( because of absorption?)

Sorry I don«t have anything to contribute to the discussion, but your articles are better researched and have better sources than any articles I have been able to find.

regards,
globesetter





Korn Posted: Mar 22 2004, 04:31 PM


Any spirulina experts in here? :)



phillip888 Posted: Mar 25 2004, 11:26 PM


Well, I'm not an expert otherwise I'd be trying to create super B12 spirulina, but simply put, spirulina is an organism that is, in some ways similar to bacteria that create B12 in the soil, but it's actually an evolutionary branch-off. It's called a micro-algae or blue-green algae. It's basically something that isn't bacteria but isn't algae, think of it as plant based bacteria. The same formation of B12 can take place in spirulina as a B12 (culture) laboratory vat. The primary issue with spirulina is that it's usually grown for protein, EFAs, and anti-oxidants(like chlorophyll, not for B12 production. This means that without cobalt explicitly added to the growth pond(which is usually not the case) another B12 'analog' is formed. Now some manufacturers claim human form B12 is in their spirulina product. In order for this to be true, they would have to add cobalt solutions to their growth ponds.

The bad side of spirulina is the same as bacteria, contamination and mutation. Spirulina, like bacteria, can mutate to a pathogen, or toxic compound producing form in one generation. Any spirulina farmer has to test batches for this with every harvest, making home spirulina harvesting just about impossible (well, unless you're willing to take some risks).

The reason you hear conflicting information is simple. Not all spirulina makes cobalamin because of a lack of useable cobalt. That's why you see vegan pages saying it's not a dependable source, they don't know (or don't have the resources) to look at every brand and source.

Oh, and the only B12 that is 100% human useable is made by chemists in a lab. You will not find it in the wild.



Korn Posted: Mar 26 2004, 01:18 AM


Thanks, Philip. I don't know if you have read about the experiment where they tried to cure B12 deficiency with B12 extracted from human faeces, and the B12 they managed to extract actually was reported to cure the deficiency, even if it contained 95% inactive B12 analogues, in other words only 5% active cobalamin. There has also been reports on analogues in fortified food. And in multivitamin supplements, due to the contact with copper/iron. If it is correct that processes in healthy human beings actually distinguish between active B12 and the inactive analogues, it doesn't seem that it really is a problem that B12 are not 100% 'human useable' It surprises me that some 'experts' seem to claim that all B12 in plants is useless 'because it contains B12 analogues'...

Anyway, do you know what functions the B12 analogues in our bodies perform?



phillip888 Posted: Mar 26 2004, 11:28 PM


I've heard of the B12 extraction from human waste before, but never found any papers. I'll have to check it out again. I've been looking for a simple home B12 production solution for a while(that's why I know about spirulina). Currently you can't really do anything B12 related without expensive lab equipment and a controlled environment.

I'm guessing that our body doesn't block cobalamin absorbtion just because B12 analogs are absorbed. I've yet to find any scientific reasoning or proof for that idea, but I see it written everywhere. I can't imagine that the human body does anything special with B12 analogs, but I have no idea really. Considering the current knowledge of B12, analogs may very well be needed too. It's not like they didn't exist before, and they're as abundant or more so than cobalamin and it's derivatives. Evolution is based on environment, so it makes sense that our body can at least pass the B12 analogs that have been present since day one...



Robin Posted: Mar 31 2004, 01:58 AM


QUOTE (Korn @ Mar 22 2004, 04:31 PM)
Any spirulina experts in here? :)


This is a very good source for earthrise spirulina and chlorella: http://www.holistikum.de

regards, robin

Korn Posted: Mar 14 2004, 01:33 PM


Pfizer Pharmacia has a swedish site called www.b12.brist.com (http://www.b12.brist.com) ('brist' = deficiency).

If you happen to read a Scandinavian language you might order pamphlets and a couple of books on B12, homocystein etc from this site. In one of them, 'Folat, vitamin B12 och graviditet', they state that inactive B12 analogues can be created from contact with copper, iron and vitamin C. They also write that Americans studies have shown that multivitamins, that often contain trace minerals in addition to vitamin C, often contains B12 analogues. Additionally, they state that American scientists warns people against B12 in multivitamin supplements.

If you look around, Pfizer might have sites in other languages too.







This link ( http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=6126492&itool=iconpmc ) contains some interesting info.

"Presence and formation of cobalamin analogues in multivitamin-mineral pills.

Kondo H, Binder MJ, Kolhouse JF, Smythe WR, Podell ER, Allen RH.

Because the origin of cobalamin (vitamin B12) analogues in animal chows and animal and human blood and tissues is unknown, we investigated the possibility that multivitamin interactions might convert cobalamin to cobalamin analogues. We homogenized three popular multivitamin-mineral pills in water, incubated them at 37 degrees C for 2 h, and isolated the cobalamin. Using paper chromatography we observed that 20-90% of the cobalamin was present as cobalamin analogues. Studies using CN-[57Co]cobalamin showed that these analogues were formed due to the concerted action of vitamin C, thiamine, and copper on CN-cobalamin. These cobalamin analogues are absorbed from the gastrointestinal tract of mice and either fail to stimulate or actually inhibit cobalamin-dependent enzymes when injected parenterally. We conclude that CN-cobalamin can be converted to potentially harmful cobalamin analogues by multivitamin-mineral interactions and that these interactions may be responsible for the presence of cobalamin analogues in animal chows and animal and human blood and tissues."

[Korn]

From http://www.cyanotech.com/pdfs/spirulina/spbul52.PDF


Spirulina Pacifica as a Source of Cobalamin Vitamin B-12

Vitamin B-12 is actually a family of derivatives, some forms being active for humans and other forms which are not. The active form, cobalamin, is of significant interest to strict vegetarians because this particular vitamin is essential for normal maturation and development of blood cells (erythrocytes), but it is not normally obtained by consuming pure plant foods. The ultimate source of all vitamin B-12 is derived at the microbial production level. Although plants and animals cannot synthesize or store vitamin B-12, it is effectively passed through the food chain, accumulated and recycled by animals. Therefore, vitamin B-12 is abundant within animal products such as fish, meat, eggs and milk and lactoovovegetarians or lactovegetarians ingest an ample supply for normal functions (Herbert 1994).

The discovery of vitamin B-12 was from studies of a previously incurable disease, pernicious anemia. The condition is nearly identical to folate deficiency but leads to irreversible degeneration of the nervous system if left untreated. Two Harvard physicians, George Monot and William Murphy, found in 1926 that symptoms of the disease could be alleviated by feeding patients large amounts of raw liver, they described this active "liver factor" as vitamin B-12. In 1948 vitamin B-12 was isolated and crystallized, but it was not until 1957 that a combination of chemical methods and x-ray diffraction was utilized to ascertain the precise molecular structure. Subsequently, it has been shown that vitamin B-12 is required for two key enzymatic steps in mammalian metabolism, synthesis of methionine from homocysteine (methionine synthetase) and the isomerization of methylmalonyl-CoA to succinyl-CoA (methylmalonyl-CoA mutase). The latter reaction is involved the catabolism of odd-chained fatty acids and several amino acids. Because of reduced flux through the methylmalonyl CoA mutase reaction, abnormalities in fatty acid metabolism likely cause the subsequent neurological tissue damage.

Pernicious anemia is a disease of the stomach that initiates as megaloblastic anemia. Normally, the gastric tissue secretes a glycoprotein called "intrinsic factor" which complexes with ingested vitamin B-12 in the digestive tract and helps promote its absorption through the small intestine and into the bloodstream. The affliction of pernicious anemia results from the lack of secreted intrinsic factor and resulting deficiency of vitamin B-12 absorption. Uncomplexed vitamin B-12 can be absorbed, but with such low efficiency that massive doses must be administered to prevent or cure the disease. Ulcer patients or those that have undergone stomach removal often have special requirements to prevent pernicious anemia.

Not all forms of vitamin B-12 produced by microbes are metabolically active for mammals. Some forms are termed "analogs" or "corrinoids" because they are sufficient for enzymatic reactions and the growth of microorganisms, but do not fulfill the specific roles in humans. The vitamin B-12 molecule has four characteristic components that determine whether it is "human-active" or not. The largest constituent and core of vitamin B-12 is the corrin ring system which is somewhat similar to the porphyrin ring system of hemoglobin. At the heart of the corrin ring is cobalt, which can be bound to various adducts and still remain human-active (depicted as an "R"). The "R" adducts can be one of two types, either a methyl group as in methylcobalamin or 5'-deoxyadenosyl known as coenzyme B-12 and provide human activity.

Additionally, humans have the enzymatic machinery to convert other "R" groups such as a hydroxocobalamin and others into one of the two types of active cobalamin adducts. The dominant forms in meat are adenosylcobalamin and hydroxocobalamin, whereas dairy products (including human milk) contain primarily methylcobalamin and hydroxocobalamin (Herbert 1987). Because cyanide stabilizes the cobalamin molecule so well, cyanocobalamin is the chemical form of the molecule most often produced in commercial formulations, usually by microbial fermentation. This form is water-soluble, heat stable and when taken orally it is converted to forms nutritionally active to humans by exchange of the cyanide group. The other three vital components of the cobalamin structure are aminopropanol, a sugar group, and a nucleotide (Figure 1). Microbes synthesize various combinations of these four components, however all four units must be present to be active for humans. Thus, the vitamin B-12 family encompasses both the analog ñcorrinoidsî that contain corrin and some of the side chains which can be utilized by only bacteria and algae, and the specific human-active form with corrin and all three side chain components, specifically called "cobalamin".

[...]

A majority of scientific papers and nutrition information lists total vitamin B-12 activity as the sum of both human-active and the analog values. This is a result of the current official assay that is used to report vitamin B-12 activity in foods and feeds. The standard US Pharmacopeia (USP) method employs a water extract of the test sample that is fed to a special B-12-deficient strain of the bacterium, Lactobacillus leichmannii. The amount of vitamin B-12 in the sample can then be determined by the amount of growth from the bacterium. The underlying flaw of the assay is that what is active for the bacterium is not necessarily active for humans. That is, L. leichmannii responds to non-cobalamin corrinoids, which in turn leads to erroneously high vitamin B-12 measurements.

Clearly, a new standard assay is needed other than the current USP standard to accurately determine human-active vitamin B-12 from analog corrinoids. One assay has been developed using a technique called differential radioassay (Herbert 1984;Herbert 1985). This procedure uses the test mixture to first measure the total content of corrinoids by using a binder that attaches to the corrin nucleus. Then, the human-active fraction is assayed by using a substance that attaches to both ends of the cobalamin molecule, the corrin end and the nucleotide end. By subtracting the cobalamin fraction from the corrin fraction one can determine the amount of analog and human-active in a mixture, thus the term, "differential radioassay of analogs".

Other radioisotope dilution assays (RIDA) have been developed and commercialized into kits, but the diagnostic credibility of RIDA has been discredited because of inconsistent sensitivities to metabolically inactive B-12 cobalamins (Kolhouse 1978;LeFebre 1980;Oxley 1984) Fortunately, an alternate microbial growth assay has been verified which is highly specific for human-active vitamin B-12. It has been demonstrated that an isolate of the microorganism, Ochromonas malhamensis, requires vitamin B-12 for growth, but responds only to the humanactive cobalamin form unlike L. leichmannii. As in the USP assay, a water extract of a test sample is be fed to this organism, and the cobalamin concentration can be accurately calculated from the growth curve. Thus, the O. malhamensis assay may be the ñgold standardî for metabolically active B-12 that researchers have been seeking (Baker, 1986;Ford, 1953). Although this procedure is the most specific assay for 'human-active' cobalamin B-12, it has not been adopted as the USP standard yet.

The normal omnivorous American diet contains 5-15 micrograms of vitamin B-12 per day of which the excess is continually accumulated and stored in the liver throughout life (Herbert 1987). Normal humans have the ability to reabsorb vitamin B-12 very efficiently through the recycling of bile, which also serves the function of removing inactive forms of vitamin B-12 from the active forms. About 5-10 micrograms of vitamin B-12 may be secreted in the bile each day, but 3-5 micrograms of that is resorbed to the body through enterohepatic recirculation. This reabsorption of bile vitamin B-12 accounts for the fact that it takes about 20-30 years to deplete stores of vitamin B-12 after one discontinues dietary B-12 consumption, whereas those with absorption deficiencies or metabolic dysfunction may deplete in 3 years.

As body stores begin to decline and daily bile output of B-12 falls, reabsorption efficiency rises to nearly 100%. A vegetarian may at times obtain more cobalamin from enterohepatic recirculation than from dietary sources (Kanazawa and Herbert, 1983; Herzlich and Herbert, 1984;Herbert 1988).

An additional non-dietary source of absorbable vitamin B-12 may be from bacteria in the small intestine of humans (Herbert 1984, Albert 1990). Intestinal bacteria can produce 5 ug of cobalamins and 95 ug of B-12 analogues per 24 hours. Thus, vitamin B-12 deficiency can be attained by inadequate ingestion over decades, defective absorption or utilization (metabolic defects), increased requirement (pregnancy, hyperthyroidism), increased excretion (alcoholism), or increased destruction as by megadoses of vitamin C (Herbert, 1994). The most common cause of omnivore vitamin B-12 deficiency is a defect in gastric/pancreatic metabolism, small intestinal dysfunction or age-dependent loss of gastric secretory activity (Herbert 1984).


Studies of normal patients with no stores of cobalamin have shown that only 1 microgram per day is required to quickly reverse early pernicious anemia. A dramatic increase in young red blood cells and reticulocytes and a rise to normal hemoglobin and hematocrit was observed within days. The minimum daily requirement (MDR) for cobalamin appears to be even lower, 0.2-0.25 micrograms per day absorbed from food is adequate for normal people (Herbert 1987).

It has been found that a significant percentage of the activity in 'B-12 enriched' foods are inactive analogs. Hamburger, cottage cheese and boiled eggs averaged about 10% analogs while milk products (whole, evaporated, nonfat) averaged about 30%, whereas nearly 100% is inactive from tempeh. A typical 'VA lunch' consisting of potato soup, cottage cheese, lettuce, peaches, crackers, butter and milk was analyzed and found to contain 40% inactive analogs (Herbert 1984b). This is not a problem for normal people, as it has been established that inactive B-12 analogs exist in human liver, red blood cells, brain and mineral and vitamin supplements (Kanazawa 1983;Herbert 1982). Normal humans are able to discriminate between the active and non-active forms as both have always been in nature and in foods.

For example, the role of the plasma transport proteins transcobalamins I and III are to deliver non-functional B-12 analogs to the liver for discard in the bile (Burger, 1975, Jacob 1980, and Kanazawa 1983b). Moreover, an effective enterohepatic circulation recycles the vitamin from bile and other intestinal secretions accounting for its long biological half-life. During this process, vitamin B-12 analogues are preferentially excreted while human-active cobalamins are largely resorbed (Kanazawa 1983). However, those with genetic defects in vitamin B-12 metabolism or absorption deficiencies may have special requirements to supplement diets with pure cobalamin. Such patients should be under physician treatment and guidance to closely monitor cobalamin levels.

The microalgae, Spirulina, has often been mentioned as source of vegetarian vitamin B-12. Spirulina Pacifica is a spray-dried powder or tablet produced from the bacterial microalgae, Spirulina platensis. Spirulina has also been consumed for centuries as a major source of nutrition and protein by the Kanembu people who live along the shores of Lake Chad in Africa. Spirulina is collected from the waters edge in fine-woven baskets, transferred to clay pots or gourds, and dried under the sun into small biscuits called "dihe". Dihe is combined into the majority of sauces and is eaten in about 70% of their meals, amounting to about 10-12 grams per person. In times of famine, dihe is a main ingredient of their diets (Ciferri O., 1983; Furst P.T., 1978). Spirulina has been marketed and consumed as a human food in over 60 countries, and approved as a food for human and/or animal consumption by most governments, health agencies and associations (Henrickson, 1989). Spirulina has been subjected to extensive safety studies, independent feeding studies in France, Mexico and Japan demonstrated no undesirable results or toxic effects on humans, rats, pigs, chickens, fish and oysters. There have been no negative effects reported for acute toxicity, chronic toxicity or reproduction (Takemoto K., 1982; Atatsuka, 1979; Chamorro-Cevallos, 1980). Spirulina has been classified by The Bergey's Manual of Determinative Bacteriology (Ninth Edition) as in Table 1.



Assays of vitamin B-12 in Spirulina Pacifica using the standard US Pharmacopeia (USP) method to measure total corrinoids reveals an average activity of about 7 micrograms per 3 grams of Spirulina (one serving size). Using the O. malhamensis assay in parallel to specifically measure human-active cobalamins the assay exhibits an average activity of 2.5 micrograms per 3 grams of Spirulina. These figures demonstrate that about 36% of the total corrinoid vitamin B-12 activity in Spirulina is human active. An additional non-dietary source of low amounts of absorbable vitamin B-12 may be obtained from bacteria in the small intestine of humans (Albert, 1980).

Spirulina is not an animal source, but rather a vegetarian source of cobalamin B-12 amongst many other nutrients and antioxidant carotenoids. Normal healthy vegetarians should be able to attain sufficient levels of cobalamin to fulfill their requirements with a few serving sizes daily. As before, those with metabolic defects or absorption difficulties should always consult medical advice and monitor their condition closely.



References
Albert M.J., Mathan V.I., and S.J. Baker. 1980. Vitamin B-12 synthesis by human small
intestinal bacteria. Nature 283:781-782.
Atatsuka K. 1979. Acute toxicity and general pharmacological studies. Meiji College of
Pharmacy, Japan.
Baker H., O. Frank, F. Khalil, B. DeAngells and S. Hutner. 1986. Determination of
metabolically active B12 and inactive B12 analog titers in human blood using several microbial
reagents and a radiodilution assay. J. Am. College of Nutr. 5:467-475.
Burger R.L., Schneider R.J., Mehlman C.S., and R.H. Allen. 1975. Human Plasma R-type
vitamin B-12 binding proteins. J. Biol. Chem. 250:7707-7713.
Chamorro-Cevallos G. 1980. Toxicological research on the alga Spirulina. UNIDO, 24 Oct.
1980. UF/MEX/78/048. (In French).
Ciferri O. 1983. Microbiological Reviews. Spirulina, the edible organism. December pp 572.
Ford J.E. 1953. The microbiological assay of ñvitamin B12î. The specificity of the requirement
of Ochromonas malhamensis for cyanocobalamin. Br. J. Nutr. 7:299-306.
Furst P.T. March 1978. Human Nature.
Herbert V. 1994. Staging vitamin B12 (cobalamin) status in vegetarians. Am. J. Clin. Nutr.
59S:1213S-1222S.
Herbert V. 1988. Vitamin B12 : plant sources, requirements, and assay. Am. J. Clin. Nutr.
48:852-858.
Herbert V. 1987. Recommended dietary intakes (RDI) of vitamin B-12 in humans. Am. J. Clin.
Nutr. 45:671-678.
Herbert V. Biology of disease: megaloblastic anemias. 1985. Lab. Invest. 52:3-19.
Herbert V., G. Drivias, C. Manusselis, B. Mackler, J. Eng, and E. Schwartz. 1984b. Are colon
bacteria a major source of cobalamin analogues in human tissues? 24-hour stool contains only
about 5 ug of cobalamin but about 100 ug of apparent analogue (and 200 ug of folate). Trans.
Assoc. Am. Phys. 97:161-171.
Herbert V., B.S. Drivas, B.S. Fosgaldi, C. Manuselis, N. Coleman, S. Kanazawa, K. Das, M
Gelernt, B. Herzlick and J. Jennings. 1982. Multivitamin/mineral food supplements containing
vitamin B12 may also contain analogues of vitamin B12. N. Eng. J. Med. 307:255-256.
Herzlich B. and V. Herbert. 1984. Am. J. Gastroentrol. 79:489-493.
Jacob E., and V. Herbert. 1980. Vitamin B-12 binding proteins. Physiol. Rev. 60:918.
Kanazawa S. and V. Herbert. 1983. Mechanism of enterohepatic circulation of vitamin B-
12;movement of vitamin B-12 from bile R-binder to intrinsic factor due to action of pancreatic
trypsin. Trans. Assoc. Am. Physicians 96:336-344.
Kanazawa S. and V. Herbert. 1983. Noncobalamin vitamin B12 analysis in human red cells, liver
and brain. Am. J. Clin. Nutr. 37:774-777.
Kanazawa S., Herbert V., Herzlich B. Drivas G., and C. Manusselis. 1983b. Removal of
cobalamin analogue in bile by enterohepatic circulation of vitamin B-12. Lancet i:707-708.
Kolhouse J.F., H. Kondo, N.C. Allen, B. Podell and R. H. Allen. 1978. Cobalamin analogues are
present in human plasma and can mask cobalamin deficiency because current radioisotope dilution
assays are not specific for true cobalamin. N. Eng. J. med. 299:785-792.
LeFebre R.J., A.S. Virji and B.F. Meertens. 1980. Erroneously low results due to nonspecific
binding encountered with a radioassay kit that measures ñtrueî serum vitamin B12. Am. J. Clin.
Pathol. 74:209-213.
Mollin D.L., A.V. Hoffbrand and S.W. Lewis. 1980. Interlaboratory comparison or serum
vitamin B12 assay. J. Clin. Pathol. 33:243-248.
Takemoto K. 1982. Subacute toxicity study with rats. Saitama Medical college, Japan.
Atatsuka K. 1979. Acute toxicity and general pharmacological studies. Meiji College of
Pharmacy, Japan.
Spirulina Pacifica Technical Bulletin #052 Revision Date: January 12, 1999
Contact: Dr. R. Todd Lorenz
Cyanotech Corporation
Phone: 808-326-1353
FAX: 808-329-3597
Email: tlorenz at kona.net
www.cyanotech.com

[beforewisdom]

I recently went to a 5 day vegetarian confrence where some of the speakers were Dr. Michael Klapper, Dr. Michael Greger, and Brend Davis RD. They are all vegans and they are all vegan nutrition authors.

They all said seaweeds and algaes are not dependable sources of b-12. In fact they may do more harm then good as they contain chemicals that are similar enough to b-12 to hook into the same receptor sites and block real b-12

[DontJustDoSomething, SitThere]

There's always been a bunch of vegan MDs that claim that no spirulina or other plants contain B12, and that they all only contain B12 analogs (which I guess are the "chemicals" you are mentioning. B12 analogues do hook up to the same receptors as true, active B12.
Unfortunately, very few of these authors seem to want to look at both sides of the coin: when does true B12 turn into a passive B12 analog? Why is it that a mix of true B12 and B12 analogs still have an effect?

I hope they're not paid by the pharmaceutical industry to claim what they do, but sometimes they behave as if they were. For example, they are very busy explaining how unreliable B12 source spirulina and other plants are due to the inactive B12 analogs, but why don't they mentioned that a typical 'VA lunch' (see above) contain 40% inactive analogs? Or that this is not a problem for normal people? Or that inactive B-12 analogs exist in human liver, red blood cells, brain and mineral and vitamin supplements, or that normal humans are able to discriminate between the active and non-active forms as both have always been in nature and in foods?

[beforewisdom]

There's always been a bunch of vegan MDs that claim that no spirulina or other plants contain B12, and that they all only contain B12 analogues (which I guess is the "chemicals" you are mentioning. B12 analogues do hook up to the same receptors as true, active B12.
Unfortunately, very few of these authors seem to want to look at both sides of the coin: when does true B12 turn into a passive B12 analog? Why is it that a mix of true B12 and B12 analogs still have an effect?

I hope they're not paid by the pharmaceutical industry to claim what they do, but sometimes they behave as if they were. For example, they are very busy explaining how unreliable B12 source spirulina and other plants are due to the inactive B12 analogs, but why don't they mentioned that a typical 'VA lunch' (see above) contain 40% inactive analogs? Or that this is not a problem for normal people? Or that inactive B-12 analogs exist in human liver, red blood cells, brain and mineral and vitamin supplements, or that normal humans are able to discriminate between the active and non-active forms as both have always been in nature and in foods? Dr. Michael Klapper, Dr. Michael Greger, and Brenda Davis RD are all prominent vegan health professionals. I lived with them for 5 days at this convention. They were there because they cared about the vegetarian community. They had facts and citations at their lectures.
I highly doubt what you say wasn't considered by them or that they are in the pocket of supplement manufacturers.

As per their recommendations I bought enough b-12 when I got home to last me at least a year and half. Total cost: $12. That is less then one dollar a month or less then 25 cents a week.

Nobody is getting rich off of selling vitamin b-12 supplements.

There isn't any money to be made in paying doctors to push vitamin b-12 supplements.

However spirulina is expensive, costing several orders of magnitude more then vitamin b-12 supplements. It would make more sense to believe that people are being paid off to push spirulina.

Dr. Michael Klapper, Dr. Michael Gregor, and Brenda Davis RD are degreed health professionals with a long term involvment and reputation in the vegan community. Dr. Klapper is an author and he is also a medical researcher for the vegan health study. Dr. Michael Greger has produced about 1/2 dozen videos on vegan health issues of which he donates all proceeds to vegan and AR charities. He tours the country for free to speak about health issues, living off of his savings and donations to do so. Brenda Davis RD is an author of about a half dozen books on vegan/vegetarian nutrition. Her books are sold through most vegan organizations. None of these people has any reason to profiteer off a community of which they and their famlies are a part. All of these people have stellar reputations, and no shortage of professional credentials.

I mean absolutely no offense when I write this, but I place more faith in degreed researchers whom I have met and who have presented their arguments to me, whose books I have read, and whose points are reenforced by other authrotities in the community than in an anonymous person posting on the internet.

I don't know what your professional credentials are or what professional level research you have done.

I would encourage everyone reading this message not to endanger their health......and.....spend more money....to buy spirulina in the false belief that it will supply them with adequate vitamin b-12.

[veganmike]

I should say I agree with every single word Beforewisdom wrote here.

[Korn]

Dr. Michael Klapper, Dr. Michael Greger, and Brenda Davis RD are all prominent vegan health professionals.

Let's try to avoid to compete... there are many prominent health professionals on both sides of the B12 discussion.


They had facts and citations at their lectures.
I'm sure they had :). If you read the long post about spirulina above, and have followed the discussion about B12 (and spirulina), there's no doubt that there is research supporting both that the B12 in spirulina has an effect, and research that suggest that it is useless. A good thing with a forum like this, is that we can get a step further than the superficial and often boring level the B12 discussion have suffered from for a few decades...


Nobody is getting rich off of selling vitamin b-12 supplements. B12 supplements are B I G business. It was a multi-million business even only a few years after B12 was discovered.



I mean absolutely no offense when I write this, but I place more faith in degreed researchers whom I have met and who have presented their arguments to me, whose books I have read, and whose points are reenforced by other authrotities in the community than in an anonymous person posting on the internet. Wait a little.... in most forums on the net, including this one, most people, including yourself, are anonymous. The sources for the information we discuss are not hidden. In the long post about spirulina I shared with you, there is a long reference list.


I don't know what your professional credentials are or what professional level research you have done. Again, your own or anyone else's personal history of professional research isn't that relevant if the basis of a discussion are studies that are public. Plus, nobody in this thread ever suggested that vegans with low B12 levels should not take B12.

Regarding the term 'reliable sources': if some B12 sources aren't 'reliable' from a scientific viewpoint, the important question is why. Normally, in science things doesn't happen 'by themselves'. Things have reasons. If some tempeh contains a lot of B12, and other tempeh doesn't, vegans should be interested in knowing why. The same goes for spirulina.

I'm sure you have noticed that 'experts', not only vegan experts, very often disagree strongly with each other. I'll rather discuss and dive into topics that are unclear to many vegans than to cut off a potential interesting discussion by saying what Jack Norris and his colleges always say: "Don't worry, just eat your pills".

Let's not forget that this is a thread about spirulina, and not about taking B12 or not. I hope we can get further in our B12 related discussions than the just concluding with the standard 'Eat your pill'-post and a reference to one of Jack Norris' sites. We've had that a number of times already.

[DontJustDoSomething, SitThere]

I mean absolutely no offense when I write this, but I place more faith in degreed researchers whom I have met and who have presented their arguments to me, whose books I have read, and whose points are reenforced by other authrotities in the community than in an anonymous person posting on the internet.

I am not a source, and maybe you're not a scientist yourself. Besides, I'm asking some questions, questions that many long term vegans ask.


I don't know what your professional credentials are or what professional level research you have done. Why are my professional credentials relevant? The few facts I mention are documented in literature about B12, some of them come from the article about spirulina earlier in this thread. I know you don't mean I need to be a professor to ask some questions. :)

Do you ever check sources? I do sometimes, and I know a little bit about one of the articles on the list (Herbert V., G. Drivias, C. Manusselis, B. Mackler, J. Eng, and E. Schwartz. 1984b. Are colon bacteria a major source of cobalamin analogues in human tissues? 24-hour stool contains only
about 5 ug of cobalamin but about 100 ug of apparent analogue (and 200 ug of folate). Trans. Assoc. Am. Phys. 97:161-171.) Check it out, you'll be surprised about their findings.


I highly doubt what you say wasn't considered by them or that they are in the pocket of supplement manufacturers. I know a little about the doctors you mention, and I don't think they're in the pocket of the supplement manufacturers either. Especially M. Klaper seems like a great guy, I have one of his books. There are many reasons to stress the importance on B12, and especially for a doctor, unless you want to get in legal trouble. I think their legal responsibility and risk is a main reason some of them for example are afraid of letting their patients know that even if you consume a combination of true B12 and B12 analogs, the true B12 will still have an effect. They can't risk that their readers or patients will believe that for example all spirulina contains enough B12, and sue them afterwards.


Have you ever thought about why so many meat eaters, who also take vitamin supplements, develop B12 deficiency or are in the really low range? I've seen this question asked a few times, but nobody wants to reply!

[Gorilla]

my local paper printed an article about how great spirulina is, and cited it as a good source of B12 for veggies and vegans. see here:

http://thisisbrightonandhove.co.uk/brighton__hove/health/HEALTH_FEATURES0.html

[DontJustDoSomething, SitThere]

my local paper printed an article about how great spirulina is, and cited it as a good source of B12 for veggies and vegans. see here:

http://thisisbrightonandhove.co.uk/brighton__hove/health/HEALTH_FEATURES0.html

Local newspapers are unfortunately even less reliable information sources than an average vegan internet site, because the journalists write about new topics every day, and base their writings on what they find on the net. If they search for B12 and spirulina on internet, they'll find anything from "reliable B12 source" to "harmful for absorption of active B12". Anyway, good B12 source or not, it might be a great source for other nutrients.

[ConsciousCuisine]

I take a sublingual B-12 Supplement. I drink and eat B-12 and calcium fortified foods several times a week. I also eat Spirulina as it is a blood purifier and builder and it has active enzymes and good proteins and minerals and is in my Superfood from Dr. Schulze.

[phillip888]

Oh wow, I missed this completely. Korn that was a great post. It explains a lot of things that I hadn't linked together in my own research.

Also the bickering about 'my scientist can beat up your scientist'. Well, this isn't a competition, and I'm sure none of them are looking for loyalty, evangelization, or anything but the truth. Mysticism and science do not mix, so you know, look at the theories not the idols, and no creating dogma, it smells. The prominent vegan scientists are just that, scientists. If they're medical doctors they probably do not specialize on in-depth microorganism studies, and even if they do, they are capable of being wrong. They read the same papers that are available to you and me most of the time, and they apply their existing knowledge.

I think their assertion that there is no reliable plant source for B12 is simplified to the point of misleading those who do not understand biology or nutrition, or the scientific method for that matter. Many seaweeds are grown in different areas, seasons, and many are grown in vats. That makes seaweeds an unreliable source of sufficient B12 to match the USA and UK RDA. That's it. It's not that there isn't B12 there, or that some seaweed isn't full of B12, it's that there may not be enough in the seaweed you buy. With spirulina, genuine spirulina produces B12 as long as it has cobalt to use, just like bacteria it has the same requirement for cobalt. If another species is grown and labeled spirulina, well it may not be a B12 (human active) organism. There are at least two spirulina growers that have proven that their product has human active B12 insufficient amounts, but spirulina labeled bins at the health-food store may not be one of those brands, or an entirely different micro-algae. Also spirulina has a shelf life that doesn't take B12 breakdown in to account, and people think it's clever to put it in translucent bins where the whole food breaks down from UV exposure and heat.


So I think I've found my home B12 (and super-food) solution, as I'm escaping from the rat race soon. Spirulina and mushrooms are my friends. They also are completely compatible with each-other.... mmm home made swamps.

[Korn]

Here is the link to the source: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=370297 :

[Korn]

Excerpt from "Where's the B12?" by John David Mann, Mark Nathaniel Mead and David Yarrow, reprinted from SOLSTICE magazine #39, February 1989 (http://www.championtrees.org/yarrow/whereb12.htm):

"Zero... * * *Zero... * * *Zero..."

Sylvia Ruth Gray stared at the test results in disbelief.
* * * Swiss cheese... * * * * *Zero...
* * * Chicken breast... * * * *Zero...
* * * Beef heart...
* * * * * *—considered second only to liver in B12 richness...
* * * * * *—surely this must register...
* * * * * * * * * * * Zero...

Three samples purchased in normal stores at random by the lab director himself, tested, and retested for vitamin B12 content. All would be expected to show at least some B12 content.
* * * * * * Zero....

Here, so to speak, was the beef.
Where's the B12?!

The figures had the eerie chill of a flat EKG reading in a hospital emergency room.
To Sylvia Ruth Gray, their meaning was just as ominous.

What began as investigation to assure or corroborate her suspicions that our food supply's B12 content is on a steep decline—exploded a nutritional bombshell. More than a commentary on modern food, the test results—if proved correct by second and third tests—underline a problem of far reaching scope. The global eco-crisis may have infiltrated unmistakably into America's grocery stores, kitchens and bloodstreams.

Gray was shocked—but hardly surprised. Since controversy over waning B12 content in vegetarian foods first erupted several years ago, she'd spent scores of hours reviewing and analyzing the B12 literature and corresponding with some of the fields leading authorities.

She knew a B12 alarm was going off all over the planet—and few were listening.

The "Vegetarian B12" Crisis

One alarm surfaced in the natural foods community in the past several years. A spate of articles last year in East West, Macromuse and other dietary/ health journals cast concern over adequate B12 in a narrow framework as a vegetarian problem, with possible B12 deficiencies especially in the macrobiotic community and macrobiotic diet scheme.

Concern over "vegetarian B12" crystallized in January 1988 American Journal of Clinical Nutrition report on B12 in 17 macrobiotic mothers and their infants.

Lab tests by Bonnie Specker, PhD at Univ. of Cincinnati Medical Center Dept. of Pediatrics and Harvard Epidemiologist Donald Miller, MS, showed 56 percent of the subjects don't get enough B12 for normal cell function. Two infants showed signs of possible neurological damage, quickly corrected by B12 supplements.

To researchers' surprise, mothers who regularly consumed various seaweeds—previously thought to be rich sources of the vitamin—were among the most deficient. Moreover, many who regularly ate fish showed low B12 levels.

What was going on here?

Specker and Miller soon completed a larger study of 169 macrobiotic adults and children in the Boston area: 51 percent of the adults had B12 levels below the range considered "normal" by nutritionists—though no macro mom showed outward signs of deficiency, and some with over a decade of macrobiotic background showed "normal" serum B12 levels.

Meanwhile, across the Atlantic, Dutch scientists were studying 50 macrobiotic children in Holland, aged ten to 20 months. Pieter Dagnalie, MS, of the Wageningen Agricultural University told East West that low serum B12 levels and enlarged red blood cells (a B12 deficiency symptom) was observed in 12 of the 50 children.

The studies in and of themselves weren't conclusive indictment of the B12 value of macrobiotics. For one, Specker/Miller studied macrobiotics from one small geographic zone who may not represent the continental macrobiotic community. Also, risk factors like alcohol and cigarettes weren't considered in either study. But high-profile instances of severe B12 deficiency in New England macrobiotic children gave scientists' reports human faces and urgent tones.

That May an East West article titled "The Myth of Vegetarian B12" ignited fierce controversy over the B12 value of vegetarian—and especially macrobiotic—dietary practices. Almost overnight many people began eating more animal foods as a hedge against B12 deficiencies.

What is the right answer? What is the problem's exact scope and nature?

Second Thoughts

The articles didn't sit well with Sylvia Gray. "I was very disturbed," recalls Gray, "since they were not addressing the key issues. After careful review of major B12 texts (over 50 articles), I bombarded leading B12 scientists with letters, asking questions and offering perspectives."

Macrobiotic mom with a background in pre-med, medical terminology and related fields, Gray was armed with indefatigable curiosity and grasp of detail, yet held no title to expertise in B12 biochemistry. Instead of being dismissed as layperson, her inquiries were taken seriously. One authority offered to present her concerns at an international symposium.

Her homework confirmed a gut feeling: critical aspects of the B12 controversy aren't getting a hearing. For one, she explains, "B12 deficiency and issues around it are problems in the general populace, not just macrobiotics or vegetarians." Indeed, B12 weaves a biochemic plot rife with surprise twists.

Supply-Side Dietetics?

First, it's simplistic to assume low-B12 diet is the sole, sufficient cause of B12 deficiency. If this is true, how to account for the fair percent of macrobiotic mothers with normal B12 and stable physical condition after ten years or more?

Theoretically, it is difficult to become deficient with even marginal amounts of B12 in diet. For example, if dietary B12 decreases, the intestine compensates to absorb a higher percent. Over 75 percent of what passes into bile to be excreted is recycled through the small intestine.

Also, a human body tenaciously stores B12 for years. Adult bodies store 1,000 times the daily requirement. And our small intestine hosts bacteria that synthesize small but ample amounts of B12.

Several factors complicate the picture. For one, demand surges in pregnancy and breast-feeding, so nursing infants and mothers are most at risk. Also, modern life presents hosts of "B12 antagonists" to inhibit B12 absorption or use.

So while one person may assimilate, utilize and conserve B12 quite well from a diet with minimal B12, another may consume B12-rich foods, yet actually be more at risk of deficiency. Emphasis on foods' B12 content must be balanced with our varying B12 capacity. We'll explore specific, individual dietary factors that can hinder or enhance B12 utilization.

B12 in America

Specker/Miller and Dutch studies beg a larger question: How does the macrobiotic population compare with the general population? There are more clues than answers—but the clues are ominous.

In 1985 Dr. Ralph Carmel of So. California University Medical Center reported a monthly rate of 30 patients with low serum B12, less than a third of whom had typical signs of blood deterioration.

In 1987 a study in the Journal of Laboratory and Clinical Medicine (April 1987) found a condition involving "subtle absorptive dysfunction... may be relatively common" in Americans. "Subtle absorptive dysfunction" is seen increasingly in people with unexplained low serum B12—those with adequate Intrinsic Factor ("IF", which assists in B12 utilization) and sufficient dietary intake.

Adequate dietary B12; no clinical symptoms; yet, B12 problems. Could B12 malabsorption be the rule in America, rather than exception?

The question isn't as easy to answer as it seems, for what constitutes reliable testing is as fraught with controversy as the question of foods' B12 content.

"This Is Only A Test..."

One alarm triggered by East West's article was the finding many vegetarian and macrobiotic staples' B12 ratings didn't stand up to "new, improved" radioassay-plus-purified-IF analysis. By the new tests, what was believed B12 by older bacterial tests was found to be part "true" B12, but in greater part "B12 analogue"—pseudo-B12 that serves no B12 function and can actually inhibit B12 utilization.

For macrobiotics and vegetarians, reliable B12 sources such as pickles, tempeh, shoyu, miso, seaweed, bluegreen algae were suddenly in doubt. Had we been deluding ourselves? One East West reader angrily denounced macrobiotic teachings (and teachers) that assured adequate B12 in such sources.

Working Out the Bugs

Since Pasteur's premature conclusion about the microbial origins of disease (a position he later refuted), modern man has waged a losing war on bacteria. Losing, not only because microbes are infinitely more adaptable (and far more numerous!) than we humans, but also because if we win the war on bugs, we'll destroy ourselves as well, for bacteria form critical and irreplaceable links in the food chain.

The simple truth of B12 is neither we, nor animals, nor plants, make B12. It is produced only by bacteria. B12-producing bacteria dwell not only in our own intestines and intestines of ruminants (cattle, deer, camels, sheep), but also in the intestines of Earth itself: soil.

B12 is the only vitamin synthesized solely by microorganisms. And the only enzyme containing trace element cobalt. In fact, B12-producing bacteria can't synthesize B12 without cobalt. B12 owes its chemical name—cobalamin—to the cobalt core of its molecular structure. Cobalt is an essential element for humans and all vertebrates—but only assimilated in the form of B12.

Then came a plot twist. Sylvia was convinced radioassay wasn't the atomic clock of accuracy it was said to be. It requires delicate stability, and the testing medium easily becomes too acid for accurate results. Gray believes microbiological test with Ochromonas malhamensis, is superior. "A wealth of research shows O. malhamensis far more specific [for true B12] than Specker's radioassay-with- purified-IF," Gray insisted.

Investigating the accuracy of different tests, we questioned a leading authority on B12 and were assured emphatically the new radioassay is the most reliable. For corroboration, we were referred to O. malhamensis expert Dr. Herman Baker, Ph.D., professor of Preventive Medicine at New Jersey College of Medicine. To our surprise, Dr. Baker refuted radioassay's reputation, contending to the contrary, O. malhemensis is the only test to screen out inactive B12 analogues. Dr. Baker told us:

"O. malhemensis is the most specific tool to analyze true B12, in biological fluids, tissues or any food containing B12. It analyzes only metabolically active forms and will not pick up any analogues. Radioassays, by comparison, are always open to criticism. While O. malhemensis is both accurate and precise, radioassay is precise but not accurate—it gives erroneously high readings."

So a most ironic picture emerges. The entire "vegetarian B12" panic—singling out non-animal foods as devalued B12 currency—may be based to some extent on a red herring. The new radioassay may be easier to administer, and therefore cheaper and certainly more convenient for large establishments—but it's misleading.

The Truth of "False B12"

So are reports of high B12 analogue ("false B12") in vegetarian fare, says Gray.

[b]Actually, B12 analogues surfaced in research in the early '50s—and not in pickles or tempeh. In 1955 British workers demonstrated analogue presence in dairy foods. By the 1970s it was clear animal foods contained abundant analogues.

Says Gray, "It's a big mistake to think only plant foods like seaweed and algae have analogues. The stuff is ubiquitous."

Asked what factors are identified as causing increased analogues, Gray cites various environmental factors: heavy metals and chlorine in municipal water, soil mineral imbalances and deficiencies, and food refining, especially since niacin and riboflavin are required for bacterial synthesis of true B12. Moreover, says Gray, "evidence, though incomplete, suggests B12 content of both animal and vegetable foods is on a downward trend."

As example, Gray points out in 1968 beef liver samples (tested with O. malhamensis) yielded a B12 content of 122 mcg per 100 grams. Twenty years later Specker found only 3.9 mcg/100 grams in beef liver (her mean on four tests)—approximately 95 percent less!

Gray also noted non-vegetarian infants used as "controls" by Specker showed UMMA excretion—a measure of possible B12 deficiency—that were "horrendously elevated." Below 4 is considered normal, and "controls" registered over 20.

Alarmed by the beef liver and infant UMMA finding, Gray contacted a California lab to run tests using O. malhamensis. The lab's head, Dr. John Fukuoaka, purchased the foods and did repeat tests himself. Tested were Swiss cheese, chicken breast and beef heart. Tests in the '60s showed B12 levels (respectively) of 1.71, 0.5 and 14.2 mcg/100 g.

Yet Dr. Fukuoaka's 1989 tests failed to reveal any traces of B12 whatsoever!

Gray also points out the Dutch and American "vegetarian B12" studies' tests of vegetarian foods can't be taken at face value because of the testing method used, and also the wide variability in quality that certainly exists in different brands of the same food. Tempeh tested in the van den Berg (Dutch) and Specker (American) studies showed values termed "negligible" in by Specker/Miller. Yet, when Dr. Fukuoaka tested tempeh from Washington's Turtle Island Soy Dairy, it weighed in at a robust 4.6 mcg/100g!

Thus, while eating seaweeds, tempeh and certain other foods may place higher on the B12 spectrum than the panic suggested, that spectrum on the whole may be declining at a precipitous rate.

[John]

Interesting. I wonder if the findings are going to go mainstream. I'll have to keep my ears open for further news.

[Korn]

Unfortunately, the problem isn't that that these facts have not been available, they're not even 'news'..... The problem is that many sites, including some more or less pro vegan sites, just copy info from another source that looks reliable, without questioning their intentions or double checking the 'truth' they share. Humans are simple beings: as an example we often tend to believe that if something is true if told by a person with a medical education, and unquestionable if he in addition will give us references for his so called facts.

How many times have you read that 'The B12 found in plants may not be reliable because it often contains inactive B12 analogues'? And how many of these sources, vegan or not, will discuss or even mention that there are inactive B12 analogues in multivitamins, fortified food and animal products as well?

The interesting part is why even the experts that claim to be vegan fail to look at this issue from both sides?

[John]

I guess that the public doesn't realize that "the jury is still out" on B12. It seems that while people think we have it all figured out, the nature of vitamins is still a mystery to us. I mean, vitamins were only discovered about 100 years ago. Who knows how many have not even been discovered yet?

[eve]

Korn, since you've done all this research on B12, can you not give your personal opinion as to whether or not you consider we should all take a daily B12 tablet? Or a B complex tab, or a multivitamin tab? Or just cross our fingers and toes and hope for the best? :D

[Artichoke47]

It's funny you brought this up. There's a person on another who argues emphatically that she is not vegan because it's unnatural, as you have to supplement with B12 using fortified foods or vitamins. People have repeatedly told her that the animal products she eats to source her B12 also have been supplemented, i.e., the animals were supplemented with the "unnatural," as she calls it, B12. It's funny how many excuses people try to make up for not being vegan, most of them destroyed by the real facts.

[Korn]

Korn, since you've done all this research on B12, can you not give your personal opinion as to whether or not you consider we should all take a daily B12 tablet? Or a B complex tab, or a multivitamin tab? Or just cross our fingers and toes and hope for the best? :D

I have seen a lot of 'general advice' on other (vegan) sites, and in my opinion there are several reasons not to give general advice. Some suggest that you are safe the first few years as a vegan, because B12 is stored in the body: this can potentially lead people who have a B12 deficiency when they go vegan to not do anything about it for several years...

Others say that you should take really high amounts of B12 if you believe that you might be B12 deficient. But since a very high percentage of the humanpopulation will develop cancer at some point in life, and some cancer forms are associated with high B12 levels (cancer cells have ten times as many "B12 receptors" as other cells, and crave B12 for their growth), I wouldn't support such an advice either. Very low B12 levels are also associated with many health problems, and there are many elements (http://www.veganforum.com/forums/forumdisplay.php?f=38) that can trigger B12 deficiency, and to say that ie. 'as long as you eat organic vegan food, you're safe'. Experts disagree in a lot of things, including whether homocysteine is the cause or effect of heart disease, or if the inactive B12 abalogues found in plants, animal products, multivitamins and fortified food really is a problem if you're healthy.... giving advice is difficult, giving general advice is very difficult. I'll write more about this later, but for now my only advice would be to monitor your B12 and homocysteine levels, and to not trust general advice about how to 'be safe' regarding B12. ;) One thing I'm totally convinced about, is that more in-depth research is needed on B12/vegans, there are a lot of assumptions out there at the moment.

For example: non-vegans above 50 are now adviced to take B12 (and some other nutrients) on a regular basis my JAMA. Now, since the body can store B12 in the liver and other places for up to 35 years... if these meat eaters become B12 deficient at, say 55, doesn't this mean that at this age even their stored B12 reserve has been emptied? Meat eaters consume much more B12 than needed, and should higher amounts of reserve B12 than vegans. We need an average of somewhere between 0.1 mcg and 3 mcg B12 daily, and meat eaters often eat between 5 & 10 mcg daily, B12 is stored in their bodies, and eve at the age of 55 these reserves are emptied. What does that tell us? Maybe they stopped absorbing B12 at the age of 40, and have been living on reserves for 10 years? Because, if a vegan becomes a vegan at 25 and still have no health problems at 55 (without having taken any supplements), some will say that he still is living on the reserves from his days as a meat eater. We need research on people who have been vegan all their lives. And we need more research on B12 levels in plants, B12 recycling in healthy vegans, and B12 levels associated with a 'non-toxic' lifestyle (to the degree that this still is possible). There's also a lot to be found out about B12 analogues.

[Korn]

There's a person on another who argues emphatically that she is not vegan because it's unnatural, as you have to supplement with B12 using fortified foods or vitamins.
I've seen this a lot, and I must admit that the vegan movement itself partially is responsible for keeping such 'arguments' alive...


People have repeatedly told her that the animal products she eats to source her B12 also have been supplemented, i.e., the animals were supplemented with the "unnatural," as she calls it, B12. Yes, many meat eaters don't know that factory animals also gets extra B12/cobalt, vitamin D (I don't know how widespread this is).


It's funny how many excuses people try to make up for not being vegan, most of them destroyed by the real facts.
If there only were more gourmet vegan restaurants around, it would be a lot easier for most people to agree that eating vegan is a good idea. They often think that vegan food is 'what they eat, minus the animal products' - which you would need to be an masochist to live on for more than a weekend.... :)

[Korn]

Another study* found that vitamins B1, B3, C, and E, and copper and iron can damage B12. They tested 15 multivitamin preparations used daily by approximately 100 million Americans for inactive B12 analogues and all preparations contained some (6-27% of total corrinoids).



Source:
*Herbert V, Drivas G, Foscaldi R, Manusselis C, Colman N, Kanazawa S, Das K, Gelernt M, Herzlich B, Jennings J. Multivitamin/mineral food supplements containing vitamin B12 may also contain analogues of vitamin B12. N Engl J Med. 1982(July);307(4):255-6.

[Korn]

While the article in the initial post in this thread claimed that "about 36% of the total corrinoid vitamin B-12 activity in Spirulina is human active", this (http://www.spirulinasource.com/earthfoodch2b.html) commercial site refers to a study that shows spirulina has only 20% of the 'original' B-12. Here's what they write:
http://www.spirulinasource.com/imagese/C206ChartVitamin.gif


Ten grams contain 20 mcg of Vitamin B-12, 330% DV, using the approved microbiological assay. Vitamin B-12 label content claims for foods and dietary supplements are based on the approved microbiological assay. This method is used for spirulina, because it is being compared with the B-12 content of other foods and vitamins.

An alternative method developed in the 1980s, radioassay, has measured the B-12 assumed to be bioavailable to humans. Radioassay found higher levels of B-12 analogs and lower levels of bioavailable B-12 in all foods and supplements, and shows spirulina has only 20% of the original B-12. Even using these lower levels, it is the best non-animal source of Vitamin B-12.

Some incomplete research has suggested B-12 analogs could block B-12 absorption, based on limited results with very few individuals, and did not consider B-12 non-absorption due to folic acid or other dietary deficiency. In nearly 20 years, there have been no complaints of a vitamin B-12 deficiency from spirulina consumers, including children and vegetarians.

One tablespoon provides significant quantities of thiamin (23% DV), required for functioning of nerve tissues, riboflavin (23% DV), needed to gain energy from carbohydrates and proteins, and niacin (7% DV) needed for healthy tissue cells. Spirulina is a richer source of these vitamins than common whole grains, fruits and vegetables and some seeds.

Other B vitamins, B-6, niacin, biotin, panthothenic acid, folic acid, inositol and Vitamin E are also present in smaller amounts.


IMO it isn't fair to claim that "there have been no complaints of a vitamin B-12 deficiency from spirulina consumers", because B12 in spirulina is a controversial topic. It's so controversial that I'm tempted to eat spirulina daily for a few weeks and check how it will influence my B12, MMA and homocysteine levels...

[Korn]

Here's some more info about the percentage of B12 in animal foods that actually is bioavailable (from http://www.ebmonline.org/cgi/content/abstract/232/10/1266 ):


The usual dietary sources of vitamin B12 are animal foods, meat, milk, egg, fish, and shellfish. As the intrinsic factor-mediated intestinal absorption system is estimated to be saturated at about 1.5–2.0 µg per meal under physiologic conditions, vitamin B12 bioavailability significantly decreases with increasing intake of vitamin B12 per meal. The bioavailability of vitamin B12 in healthy humans from fish meat, sheep meat, and chicken meat averaged 42%, 56%–89%, and 61%–66%, respectively. Vitamin B12 in eggs seems to be poorly absorbed (< 9%) relative to other animal food products. In the Dietary Reference Intakes in the United States and Japan, it is assumed that 50% of dietary vitamin B12 is absorbed by healthy adults with normal gastro-intestinal function. Some plant foods, dried green and purple lavers (nori) contain substantial amounts of vitamin B12, although other edible algae contained none or only traces of vitamin B12. Most of the edible blue-green algae (cyanobacteria) used for human supplements predominately contain pseudovitamin B12, which is inactive in humans. The edible cyanobacteria are not suitable for use as vitamin B12 sources, especially in vegans. Fortified breakfast cereals are a particularly valuable source of vitamin B12 for vegans and elderly people. Production of some vitamin B12-enriched vegetables is also being devised.

Eggs are often mentioned as 'reliable' B12 sources, even by vegan and vegetarian 'experts'. One large (poached) egg contains approx. 0.3 mcg - 04.mcg B12 according to various sources. If the numbers above are right 91% of this B12 may never be absorbed. If we say that an egg contains 0.35 mcg B12, and 91% is not absorbed, only 0,0315 mcg of the B12 in this egg will be absorbed. Using the same kind of logic that sometimes are used when talking about how much spinach a vegan would need to get enough B12 (from spinach alone), we could say that in order to eg. absorb 4.5 mcg B12 daily from eggs (the RDA is lower, bit some B12 enthusiasts suggest that we should have a B12 intake circa four times as high as the RDA) a non-vegan would need to eat 142 eggs daily* in order to absorb 4.5 mcg B12. Even if we would say that he would ned to absorb only 1 mcg B12 daily, he would need to eat 31 eggs daily.

Before someone chimes in and say that we don't even need to absorb as much as 1 mcg B12 daily (depending on lifestyle and other factors), this may be correct - but then again, if it's correct that a healthy person don't need to absorb more than, say, half a microgram B12 pr. day or maybe even less, the amounts of B12 found in some plants don't look that bad either. Not that eating 142 portions of anything serves a good reference for a reliable source of anything, but IMO we should look at the bare facts and debunk as many myths about 'reliable' sources as possible.

Egg may not contain a lot of B12 compared with some other animal products, but one portion of roasted chicken or roasted turkey (3 ounces, or 255g) have B12 levels similar to one egg (0,3 mcg), but a higher amount of absorbable B12. Still, in order to reach the intake of B12 that some vegan 'B12-fanatics' suggest (9-10 mcg daily, due to the theory that we need a lot more than the standard recommendations), a non-vegan relying on chicken or turkey for their B12 would need to eat almost 32 three-ounce portions of roasted birds daily to reach those B12 levels. That's 96 ounces (2.7 kg) roasted bird pr. day! Poor birds, and poor humans... Even if a cheeso-vegetarian would rely on brie for his B12 intake, he would ned to eat 19 ounces (538g) cheese daily to get the B12 intake we are talking about.


Vegans are said to have a higher B12 deficiency risk than ovo-vegetarians (ovo-vegetarins eat eggs), and vitamin B12 supplementation is important for people who are low in B12. I wonder if the ovo-vegetarians are aware of the fact that vitamin B12 supplementation is considered important for commercial laying hens (http://www.scielo.br/scielo.php?pid=S1516-635X2003000100006&script=sci_arttext) as well...

If we as a theoretical experiment assume that the spirulina numbers above are right (10 g spirulina apparently contain 20 mcg B12), assume that they exaggerate re. the absorption rate/bioavalabilty of spirulina... let's say we assume that spirulina has the same low absorption rate of true B12 as eggs (only 9% is absorbed), spirulina still has way more absorbable B12 than eggs - pr. gram. 255g eggs contain 0.3 mcg B12, which equals 0,0117647 mcg B12 pr. 10 g. This means that in this little mathematical experiment spirulina has 1700 times as much B12 as eggs, which are considered a reliable source of B12 in spite of it's low absorption rate. Just like spirulina, eggs have also been described as potentially blocking the absorption of true B12.

If they both may block genuine B12, and both are absorbed at a poor rate, why are eggs by many vegans/vegetarians (and others, of course)considered a much better B12 source than spirulina if spirulina has 1700 times as much B12 pr. gram as eggs? Maybe neither eggs or spirulina are useful B12 sources, but if this is the case, wouldn't it make more sense if veg*ns stopped describing eggs as a reliable B12 source? And, if the same veg*ns actually think that we need to consume 9-10 mcg B12 daily, wouldn't it make sense to mention how many (portions of) egg or eg. chicken one would need daily to reach such an intake?


* Even if humans would absorb all of the circa 0,35 mcg B12 found in eggs, one would still need to eat 20-25 eggs daily (if eaten during one meal) to get the 9 or 10 mcg B12 some vegans claim we all need in order to avoid elevated homocysteine levels and increased heart disease risk. If the egg consumption was spread throughout the day, the need would be lower, but one would still need to eat a lot of eggs.

[Korn]

"Studies of normal patients with no stores of cobalamin have shown that only 1 microgram
per day is required to quickly reverse early pernicious anemia. A dramatic increase in young red
blood cells and reticulocytes and a rise to normal hemoglobin and hematocrit was observed within
days. The minimum daily requirement (MDR) for cobalamin appears to be even lower, 0.2-0.25
micrograms per day absorbed from food is adequate for normal people (Herbert 1987).
It has been found that a significant percentage of the activity in 'B-12 enriched' foods are
inactive analogs. Hamburger, cottage cheese and boiled eggs averaged about 10% analogs while
milk products (whole, evaporated, nonfat) averaged about 30%, whereas nearly 100% is inactive
from tempeh. A typical 'VA lunch' consisting of potato soup, cottage cheese, lettuce, peaches,
crackers, butter and milk was analyzed and found to contain 40% inactive analogs (Herbert
1984b). This is not a problem for normal people, as it has been established that inactive B-12
analogs exist in human liver, red blood cells, brain and mineral and vitamin supplements
(Kanazawa 1983;Herbert 1982). Normal humans are able to discriminate between the active and
non-active forms as both have always been in nature and in foods. ".


Here's another study on whether B12 analogues actually are absorbed (in this case, in rabbits. Sorry, rabbits...) or if they are rejected before they enter the body:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=372496


Absorption, Plasma Transport, and Cellular Retention of Cobalamin Analogues in the Rabbit
EVIDENCE FOR THE EXISTENCE OF MULTIPLE MECHANISMS THAT PREVENT THE ABSORPTION AND TISSUE DISSEMINATION OF NATURALLY OCCURRING COBALAMIN ANALOGUES (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=372496)


Analogues of cobalamin (Cbl; vitamin B12) are prevalent in nature as a result of bacterial synthesis, and are of additional interest because of their potential use as antimetabolites and chemotherapeutic agents. We have synthesized 14 Cbl analogues containing 57Co and have compared their gastrointestinal absorption, plasma transport, and cellular retention to that of [58Co]Cbl in rabbits.
Many of the Cbl analogues were bound with low affinity by intrinsic factor, and none of these [57Co]Cbl analogues were taken up by the ileum or absorbed into the body in amounts comparable to that of [58Co]Cbl. The Cbl analogues that were bound by intrinsic factor with high affinity were taken up by the ileum but, in many cases, they were retained there in significant amounts.

[...]

The few analogues that were bound by transcobalamin II with low affinity were taken up by tissues in lesser amounts, and 20-70% of these analogues was rapidly excreted in the urine as occurs with native Cbl when it is present in plasma in unbound form.

[...]

These studies indicate that intrinsic factor and the ileum prevent certain Cbl analogues from entering the body and that the granulocyte R-type protein and hepatocytes prevent the dissemination of certain Cbl analogues that may gain entry such as during infections with Cbl analogue-producing bacteria.