Cobalt deficiency vs. B12 deficiency

[Mr Pearcore]

Nah, I said I have given up adding salt to meals. I havent added salt for over a month. And in the past my blood pressure was alittle low. B12 was always fine, and I havent ate animal products for around 6 years or so now. Just after giving up salt, I get low B12. But never before.

[Korn]

It is supposedly only found in animal products, which is why it is a hot issue for vegans. Hi Seaside, B12 comes from bacteria/microorganisms, so it is not correct to say that it comes from animal products...


Too much salt also throws your potassium levels out of balance, which is also bad for your heart.
Potassium is a known cobalt antagonist (B12 is based around a cobalt core). http://www.acu-cell.com/nico2.htm... Both anti-coagulant medications and potassium supplements may block the absorption of B12 (http://www.jambajuice.com/features/tobornottob.html ) Potassium is also said to make B12 more 'effective': http://www.leaflady.org/cancer.htm. Large doses of B12 should be used with caution in those with low levels of potassium (http://www.innvista.com/health/nutrition/vitamins/b12.htm). Since there seem to be a strong link between salt intake and potassium, and potassium balance and B12, it wouldn't surprise me if a link between B12 and salt intake would be documented at some point...


You may have to supplement B12, unless you include certain fermented foods like tempeh in your diet. :)
There are various studies on B12 and tempeh: some tempeh contains B12, and some does not. Since B12 is produced by bacteria/microorganisms, tempeh produced in a very anti-bacterial environment is known to contain no or little bioavailable B12...

I think humans are 'meant to' eat plants, and that we in the ideal world are not 'meant to' eat supplements, But we are not living in an 'ideal world'... Still, I wouldn't rely on tempeh for B12...

Why does (some) tempeh contain B12? (http://www.veganforum.com/forums/showthread.php?t=253&highlight=tempeh)

[Korn]

B12 was always fine, and I havent ate animal products for around 6 years or so now. Just after giving up salt, I get low B12. But never before.
It could also be that you had built up B12 reserves while eating animal products, and that they now have been 'emptied'... Did you use sea salt?

[Mr Pearcore]

Emptied after 6 or 7 years? they were always fine before, they never decreased each year.

I used any salt.

[Korn]

Animals with cobalt deficiency develop symptoms that are similar to B12 deficiency symptoms. According to this (http://66.102.9.104/search?q=cache:dZXMQlMsLgMJ:www.glenroseffa.org/ham/Animal%2520Science/Powerpoints/Minerals.ppt+depletes+the+body+b12&hl=en&client=safari) site, 'Ruminants grazing in cobalt-deficient areas show loss of appetite, reduced growth, and loss in body weight, followed by emaciation, anemia, and eventually death.'

I've read that the only way to consume B12 for humans is by consuming B12, but there is also a certain degree of B12-synthesis in human intestines.

I've also seen sources that list cobalt levels in vegetables, like radish, snap beans, onions, cabbage, mushrooms, apricots, sea vegetables, beet greens, buckwheat, dulse, figs, goldenseal, Irish moss, kelp, kidney, lettuce, pau d'Arco, sarsaparilla, spinach, watercress... one site ( http://www.3.waisays.com/nutrients.htm ) writes that 'cobalt is absorbed through vitamin B12 in fish and egg yolk (or other animal food), but dried apricot s, hazelnuts and walnuts contain cobalt too'.

Who knows more about this?

[Korn]

The Wolfe Clinic sells 'Theta Cobalt', "Angstrom size particles the way nature intended".

They write:

Cobalt is an essential mineral although the body only needs a small amount. Cobalt is stored in red blood cells with smaller amounts in the kidney, liver, pancreas and spleen. Research indicates that cobalt helps with the repair of the myelin sheath, increases the effectiveness of glucose transport from the blood into body cells (pernicious anemia), and the building of red blood cells (increases the assimilation of iron). Cobalt is an important agent of vitamin B-12, it increases the body’s ability to absorb vitamin B-12. Cobalt stimulates many enzymes of the body and normalizes the performance of other body cells. Because of its low absorption rate and high excretion rate, cobalt toxicity is not common but excess can lead to enlargement of the thyroid gland.

I don't understand their slogan 'Angstrom size particles the way nature intended'.
Someone, please enlighten me...

[Korn]

Here's another comment about cobalt vs. B12 deficiency, from http://www.saltinstitute.org/47r.html :



Cobalt deficiency has not been demonstrated in non-ruminant animals. In a few instances where cobalt has created some response, it is assumed that the diet lacked vitamin B12. It should be indicated, however, that non-ruminants also synthesize a limited amount of vitamin B12 in their digestive tract. How much is absorbed is not known, but vitamin B12 would be available in the feces for animals that practice coprophagy. Horses have thrived on pastures so low in cobalt that cattle and sheep confined to them soon waste and die. The utilization of cobalt by the microbial flora in the rabbit is much more efficient than in ruminants. The absorption of vitamin B12 by rabbits is very efficient (88). There is some evidence that cobalt may have a sparing action on zinc in zinc deficiency in pigs (92).


If the diet of non-ruminants is adequate in vitamin B12, there is no evidence to indicate a need for cobalt. It is possible, however, that if dietary vitamin B12 is limiting, a need for cobalt for intestinal synthesis of B12 will be of some importance with non-ruminant animals. All-plant diets contain little or no vitamin B12. Therefore, non-ruminant animals consuming all-plant diets would need some dietary cobalt in order to enable their microflora to synthesize vitamin B12. This fact causes many producers of non-ruminants to supplement diets with 0.1 ppm cobalt just in case the diet might not supply all the vitamin B12 required (87, 92, 93, 95, 141). Therefore, in practice, trace mineralized salt that provides cobalt, which is needed by ruminants, is also used for non-ruminant animals. This eliminates the need for manufacturing a separate trace mineralized salt for non-ruminants that does not contain cobalt. Moreover, the presence of cobalt provides some insurance in case the non-ruminant diet is lacking sufficient vitamin B12.

The question is, could any of this apply to humans as well?

[Jo1234]

What will happen if i get no B12?

[eve]

it gets manufactured in your gut.

[abrennan]

i read an article, I think it was in the latest vegetarian society mag (aust) and some was saying that cobalt is just floating around in the atmosphere and we;re breathing it in

antony

[anneh]

What will happen if i get no B12?

This link might help. Many vegan foods are fortified with B12, alternatively there are supplements designed for vegans. B12 is stored well so as the article points out, if you had plenty and then stop consuming it, it can be years before you actually become deficient.
http://www.nhsdirect.nhs.uk/he.asp?ArticleID=42

[Korn]

http://www.scorecard.org/chemical-profiles/html/cobalt.html :


Cobalt is found in the earth's crust at 0.001-0.002 percent and is found in cobalite, linnacite, smaltite, and erythrite (Merck, 1989). It is a by-product from nickel, copper, silver, lead, and iron ore refining. Green, leafy vegetables may contain concentrations as great as 0.5 milligrams per kilogram of dry weight (HSDB, 1991).
(Note: that's milligrams, not micrograms.)

http://www.coloradomining.org/materials.html :

How might people be exposed to cobalt?
People are commonly exposed to small amounts of cobalt naturally present in the air they breathe, the water they drink, and the foods they eat. For example, leafy green vegetables are a natural source of cobalt in people’s diets. Industrial workers may breathe cobalt dust or fumes, or touch substances that contain cobalt.

http://www.thecdi.com/cdi/images/documents/final%20food.pdf :

What foods in Cobalt found in?

Research suggests that the top three food groups for Co in the human diet are: milk and dairy
products, which account for approximately 32% of the total Co intake; fish and crustaceans,
which account for approximately 20%, and condiments, sugar and oils, which account for
about 16%. One investigation of specific foods (Leblanc et al., 2004) found that chocolate
contains the highest level of Co, with molluscs and crustaceans, and dried fruit and nuts also
containing the high levels in comparison to other foods.




http://www.britannica.com/eb/article-1376 :

Cobalt, though widely dispersed, makes up only 0.001 percent of the Earth's crust. It is found in small quantities in terrestrial and meteoritic native nickel-iron, in the Sun and stellar atmospheres, and combined with other elements in natural waters, in nodules beneath the oceans, in soils, in plants and animals, and in such minerals as cobaltite, linnaeite, skutterudite, smaltite, heterogenite, and erythrite. Traces of cobalt are present in many ores of iron, nickel, copper, silver, manganese, zinc, and arsenic, from which it is often recovered as a by-product.



http://www.championtrees.org/yarrow/tob12.htm :

Mark Mead reports Mn, like nickel, forms B12 analogue, and is causing widespread soil depletion of cobalt.


From Vitamin B12 and cobalt (http://www.sare.org/sanet-mg/archives/html-home/8-html/0278.html)





THE B12-COBALT CONNECTION
by Mark Mead & John Mann
reprinted from SOLSTICE magazine #34, Feb. '90

B12 is the only vitamin synthesized solely by certain
microorganisms -- many of which are abundant in soil. And the only
vitamin containing a trace element: cobalt. B12 owes its chemical
name -- cobalamin -- to the cobalt at the center of its molecular
structure. Humans and all vertebrates require cobalt, though it's
assimilated only in the form of B12.

Cobalt is important in the plant world. Bacteria on root nodules
of legumes (beans, alfalfa, clover) require cobalt (and other trace
elements) to synthesize B12 and fix nitrogen from air. Soybeans grown
without cobalt are severely retarded in growth and exhibit severe
nitrogen deficiency, leading to death in about one of four plants.
Adding only a few ounces of cobalt per acre can resolve deficiency
symptoms in ten to 21 days.

Cobalt deficiency is far more dramatic in animals, particularly
ruminants (cattle, deer, camels, and sheep) grazing on deficient
pasture. These animals obtain all their B12 from their gut bacteria,
but only if bacteria are provided cobalt salts from pasture. Legumes
with less than 80 parts per billion (ppb) cobalt can't meet ruminant
B12 needs. Under deficient conditions, calves and lambs thrive and
grow normally for a few months as they draw on B12 reserves in liver
and other tissue, but soon exhibit gradual loss of appetite and
failure to grow, followed by anemia, rapid weight loss and finally
death. Marginally deficient pastures cause birth of weak lambs and
calves that don't survive long. These symptoms mirror B12 deficiency
in human infants.

To prevent or alleviate cobalt-B12 deficiency, farmers routinely
add cobalt to animal feeds or salt licks. Some fertilize pastures
with cobalt-enriched fertilizers; others opt for periodic quick- fix
B12 injections. With any of these measures, all symptoms are reversed
and B12 in milk and colostrum dramatically increases.

The implication for humans subsisting on vegetarian diets are
profound. B12 synthesis by indigenous bacteria is known to occur
naturally in the human small intestine, primary site of B12
absorption. As long as gut bacteria have cobalt and certain other
nutrients, they produce B12. In principle then, internal B12
synthesis could fufill our needs without any B12 provided by diet.

But if cobalt in our diet is on the wane, perhaps the problem
isn't so much lack of B12-synthesizing intestinal flora as lack of
cobalt, the element with which bacteria weave their magic. The
burning question then is: how cobalt deficient is our soil?

Stalking the Wild Cobalt

Investigating soil-cobalt links, we sought perspectives of two
researchers: an expert in agricultural chemistry, another in
nutrition.

Dan Reeter, chief researcher at Bio-Systems Labs in Salida, CO,
is creating one of the world's most comprehensive computer facilities
for soil biology testing. Reeter, whose lab has served agricultural
industry for over 40 years, told us:

"I can say with certainty there's a decline of soil cobalt.
Confirm this for yourself. Simply to pick any Ag magazine -- they all
push cobalt supplements, spurred by B12-poor condition of crops."

Reeter said soil bacteria, comprising 20 percent of soil biomass,
is destroyed or inactivated by ag chemicals, inhibiting uptake and
metabolism of cobalt and other trace elements. Reeter directly traces
this problem to increasing presence and proportion of B12 analogues
("false" B12). Reeter reports his extensive tests at Bio-Systems
demonstrate plants grown in organically managed soil make
significantly higher levels of usable B12.

Robert Kay, PhD candidate in nutrition at the Univ. of
Connecticut, emphasized uncertainties in B12 research, especially in
light of new methods to measure B12 and new insights these methods
made available. He also cautioned categorization of "true" vs.
"false" B12 may be too absolute. "We no longer talk about simply
TB12,' since we now know there's many varieties of cobalamins with
varied biological action (i.e., availability). There is no 'gold
standard' in this area."

[Korn]

Here's a link to another (heated, albeit interesting) discussion about this topic: Got milk? You've got problems (http://www.mailarchive.ca/lists/misc.health.alternative/2005-08/2833.html)

[Korn]

Here's another link to an article describing that the mineral that will suffer most when processing whole wheat grain into white flour is cobalt. 89% will disappear. This could indicate that cobalt is very vulnerable. Since most humans eat more processed/dried/cooked/stored food than fresh food (eg more flour than fresh wheat grains), we get too little cobalt. This again would probably influence our ability to manufacture B12. (Look here: Does a healthy body manufacture B12? (http://www.veganforum.com/forums/showthread.php?t=12791))

For those of you who haven't read all the posts above: The B12 vitamin is unique in that it contains a cobalt atom (that's why B12 is called cobalamin). So without cobalt, there will be no B12. A cobalt deficient soil will mean that cobalt/b12 levels will be low, which also will be a problem for animals who eat grass or other plants from this soil. Cobalt is added to agricultural soil/supplements are given to livestock when needed (most met eaters still believe that they are not taking any supplements when they eat meat, but in these cases they definitely are - indirectly, they are eating cobalt/cobalamin fortified animals.

[Korn]

According to this (http://jn.nutrition.org/cgi/content/full/130/12/3038) study, "Vitamin B-12–deficient pigs fed 1 mg/kg cobalt had 47% lower homocysteine concentrations in serum than the vitamin B-12–deficient group fed 0.13 mg/kg cobalt, but the vitamin B-12 status was unaffected. "

Also:


It can be concluded from these observations that vitamin B-12–deficiency symptoms, including an accumulation of serum homocysteine, can be attenuated by nickel and cobalt, although the mode of action of these elements seems to differ. If the effects of nickel and cobalt are indeed mediated by metabolic processes, then the relevance to human nutrition is quite plausible.

If pigs can consume cobalt (without consuming B12/cobalamin), maybe we can too? It is said that non-ruminant animals cannot synthesize B12. Pigs pigs are non-ruminant animals, and still seem to benefit from cobalt. Maybe they don't actually synthesize B12 from the cobalt (the B12 molecule contains a cobalt atom), but use it 'as is'. Cobalt is found in green, leafy vegetables, some fruit, buckwheat, figs, cabbage and sea vegetables.

According to this (http://www.fertilizer.org/ifa/publicat/PDF/2004_ag_new_delhi_nielsen.pdf) source, "Cobalt deficiency may be induced by high soil manganese, or by heavy liming of soil, which reduces the amount of cobalt available to plants. Cobalt deficiency is widespread throughout wide areas of most countries in the tropics, but is found in cool, temperate regions of Ireland and Scotland."

(Liming is "the application of calcium to soil in various forms, including marl, chalk, limestone, or hydrated lime. This neutralises soil, improves texture, and increases activity of soil bacteria. However, oversupply may result in harm to plant life".)

It is claimed that humans cannot absorb cobalt unless it's a part of the B12 molecule, but people who have been drinking beer with added cobalt got severe heart problems, and overexposure (http://www.atsdr.cdc.gov/toxprofiles/phs33.html#bookmark05) to cobalt is a known issue). Please post any relevant info you come across regarding the human consumption of cobalt vs. cobalamin (B12), especially if you know of studies about how absorbing cobalt from plants may - or may not - reduce or the need to consume cobalamin from plants!

[Korn]

Another article about cobalt/B12:
http://www.dcnutrition.com/Minerals/Detail.CFM?RecordNumber=68

Some excerpts:



Ruminants (i.e.-cows, sheep, goats, deer, antelopes, giraffe, etc.) can use elemental cobalt, however, the microbes fermenting and digesting plant material in their first stomach (rumen) convert elemental cobalt into vitamin B12 which the animal can use.


Intrinsic factor is a mucoprotein enzyme known as Castle's intrinsic factor and is part of normal stomach secretions.

If a person has hypochlorhydria (low stomach acid - usually a NaCl deficiency) the intrinsic factor will not work and B12/cobalt is not absorbed - this is why doctors frequently give B12 shots to older people on salt restricted diets. Sublingual (under the tongue) and oral spray B12 is available; plant derived cobalt is very bioavailable, however, because of low salt diets and cobalt depleted soils, vegetarians frequently have B12 deficiencies.

The B12 intrinsic factor complex is primarily absorbed in the terminal small intestine or ileum; calcium is required for the B12 to cross from the intestine into the bloodstream as well as an active participation by intestinal cells.



There is an enterohepatic (Intestine direct to the liver) circulation of B12 that recycles B12 from bile and other intestinal secretions which explains why B12 deficiency in vegans may not appear for five to ten years.

The maximum storage level of B12 is 2 mg, which is slowly released to the bone marrow as needed. Excess intake of B12 is shed in the urine i.e. contributing the notion of "expensive urine".



The discovery of the essentiality of cobalt came from observing a fatal disease ("bush sickness") in cattle and sheep from Australia and New Zealand; it was observed that "bush sickness" could be successfully treated and prevented by cobalt supplements.

Bush sickness was characterized by emaciation (unsupplemented vegans), dull stare, listless, starved look, pale mucus membranes, anorexia (loss of appetite), anemia microcytic/hypochromic) and general unthriftiness.

In humans, a failure to absorb B12/Cobalt results in deficiency disease. This can result from a surgical removal of parts of the stomach (eliminates areas of intrinsic factor production), or surgical removal of the ileum portion of the small bowel, small intestinal diverticula, parasites (tapeworm), celiac disease (allergies to wheat gluten and cows milk albumen) and other malabsorption diseases. Pernicious anemia and demyelination of the spinal cord and large nerve trunks are classic for B12/Cobalt deficiency.

Less than 0.07 ppm cobalt in the soil results in cobalt deficiency in animals and people who eat crops grown from those soils; 0.11 ppm cobalt in the soil prevents and cures Cobalt deficiency.

The RDA for B12/Cobalt is 3 to 4 mcg per day. We prefer expensive urine and like 250 to 400 mcg per day, especially while preparing for pregnancy and nursing (remember a baby being nursed by a deficient mother has their deficiency extended over a long period of time and may result in serious permanent nerve damage).

Cobalt excess in man (20 to 30 mg/day) may create erythropoiesis (increase in RBC production) with increased production of the hormone erythropoieten from the kidney. Cobalt is also a necessary co-factor for the production of thyroid hormone.

Cobalt is a trace mineral nutrient for bacteria. Its only established role in animals is as a component of vitamin B12. Animals like ruminants (cows) that depend on bacteria for vitamin B12 require inorganic cobalt as a nutrient. Only microorganisms are capable of incorporating cobalt into vitamin B12.

The body cannot use unattached cobalt and cobalt supplements are therefore ineffective. Though cobalt has a low order of toxicity, overdosing with cobalt could lead to goiter and over-production of red blood cells in susceptible individuals.

Low concentrations of cobalt salts were once added to beer as an antifoaming agent. However, cobalt was incriminated in several epidemics of cardiac failure among beer drinkers. The typical American diet provides low levels of cobalt. Green leafy vegetables are the richest source, while dairy products and refined grain products are among the lowest. For example, spinach provides 0.4 to 0.6 mcg per gram, and white flour contains 0.003 mcg per gram. The oral intake of cobalt necessary to produce toxicity is many times greater than can be obtained by normal consumption of foods and beverages.

Cobalt Physiology

The only known function of Co is its participation in metabolism as a component of vitamin B12; thus the signs of Co deficiency are in reality signs of a shortage of the vitamin.



Though the most important tasks of vitamin B12 concern metabolism of nucleic acids and proteins, it also functions in (1) purine and pyrimidine synthesis; (2) transfer of methyl groups; (3) formation of proteins from amino acids; and (4) carbohydrate and fat metabolism (McDowell, 1989). Vitamin B12 promotes red blood cell synthesis and maintains nervous system integrity, which are functions noticeably affected in a deficiency.




Overall synthesis of protein is impaired in vitamin B12-deficient animals. Wagle et al. (1958) demonstrated that rats and baby pigs deprived of vitamin B12 were less able to incorporate serine, methionine, phenylalanine, and glucose into liver proteins. Impairment of protein synthesis may be the principal reason for the growth depression frequently observed in these animals (Friesecke, 1980).

[Korn]

This threads seems to need to be split in two... but before I do that, here some more info:
Green, leafy vegetables contain 20-60 mcg cobalt per 100g.
(http://apjcn.nhri.org.tw/server/info/books-phds/books/foodfacts/html/data/data5p.html)
An increased intake of cobalt increases B12 concentration, improves survival rate and increases growth rate in lambs grazing cobalt-deficient pastures. (http://www.ncbi.nlm.nih.gov/pubmed/9225420)
And here's (http://www.ncbi.nlm.nih.gov/pubmed/16230655) a study which suggests that animals on a corn- or barley-based diets deficient in Cobalt adversely affects their vitamin B12 status... and that supplemental Cobalt also decreased their MMA levels, meaning that the cobalt/B12 was active. This doesn't, of course, necessarily mean that we'd see the same results in a similar study on humans.

Also, the effect of the Cobalt supplementation was stronger in the animals not on the barley based diet. Maybe this is because barley grass (http://www.veganforum.com/forums/showthread.php?2118-80-mcg-B12-per-100-grams-barley-grass-juice) already/apparently contain good B12 levels, which at last should be bioavailable and active for non-human animals?

[vegetarian_cat]

Oh my ... This cobalt theory makes SO much sense... How come nobody mentions cobalt when talking about B12 ? After reading all this and more here and there I feel like we're on to something here.. It's soil that's depleted in cobalt and without it, we can't synthesize vit b12, so taking vit b12 supplements seems pretty absurd since our body needs cobalt in the first place.
Also, i had heard that swimming in lake waters one day would be giving me enough b12 for 2 weeks at a time (for the water one gulps in while swimming) and i now discover there's cobalt in lake waters.. Also, there's cobalt in feces, and organic veggies are often grown in soil spread with manure.. again, more cobalt rather than more vit. b12... anyway, i'll keep reading but this is very interesting..

[Korn]

Hi vegetarian_cat, I believe the reduced of the good bacteria needed to synthesize B12 more of a problem than lack of Cobalt as such - but this is pure speculation. The general reduction of natural nutrients in soil (http://www.veganforum.com/forums/showthread.php?3532-B12-in-soil-and-soil-depletion-of-nutrients) and the way we treat water (http://www.veganforum.com/forums/showthread.php?2188-B12-in-water) could possibly represent a problem for both Cobalt and B12.

[Korn]

Comparison of the dietary cobalt intake in three different Australian diets (http://www.ncbi.nlm.nih.gov/pubmed/15331342) (2004)

"Differences in the dietary intake of cobalt were assessed for vegans, lacto-ovo-vegetarian and non-vegetarian Australians using food intake logs, and daily or average trend recall over three months. A significant decrease in cobalt intake was observed for the lacto-ovo-vegetarian population compared with the intake in vegans and omnivores. There is no RDI for cobalt, however, the cobalt intake of Australians was similar to that reported in other countries. Microflora above the terminal ileum have been shown to produce significant amounts of biologically available vitamin B12. This study was unable to demonstrate a correlation between elemental cobalt intake and serum vitamin B12 concentrations in humans, as has been shown in vitro."

[Korn]

From Changes in serum concentrations of methylmalonic acid and vitamin B12 in cobalt-supplemented ewes and their lambs on two cobalt-deficient properties. (http://www.ncbi.nlm.nih.gov/pubmed/15768108)


Supplementation of the ewe with a cobalt bullet appeared to protect the growth performance of the lamb for 90 days and influence the subsequent serum vitamin B12 response in the lamb to vitamin B12 supplementation.CLINICAL SIGNIFICANCE:
Supplementing ewes with cobalt bullets in late pregnancy can improve the vitamin B12 status of their lambs, and modify their response to vitamin B12 supplementation.

This is about sheep, and not humans, but still: could this suggest that consuming more cobalt rich food (some green vegetables (http://apjcn.nhri.org.tw/server/info/books-phds/books/foodfacts/html/data/data5p.html) like broccoli and spinach, oats, some nuts etc) would affect our B12 status positively?

More about cobalt levels in food here:

http://www.thecdi.com/cdi/images/documents/Cobalt_food_Feb_06.pdf

[Korn]

Reduction of plasma homocysteine and serum methylmalonate concentrations in apparently healthy elderly subjects after treatment with folic acid, vitamin B12 and vitamin B6: a randomised trial. (http://www.ncbi.nlm.nih.gov/pubmed/14576756)


Suboptimal vitamin status is an important cause of elevated P-tHcys and S-MMA in apparently healthy elderly subjects. Oral B-vitamin therapy is an effective and convenient way to normalise P-tHcys and S-MMA.
In other words: this study suggests that taking folic acid, B12 and B9 does normalize homocysteine and MMA levels. Hcy and MMA levels are both considered useful markers for the activity in B12 (from food or supplements).

[Korn]

Age-related hearing loss, methylmalonic acid, and vitamin B12 status in older adults. (http://www.ncbi.nlm.nih.gov/pubmed/18032219) (PMID 18032219)

AbstractHearing loss has been associated with poor vitamin B12 status in some, but not all studies. This study examined a possible relationship between age-related hearing loss and poor B12 status in 93 older adults using different indices of B12 status. Hearing loss was defined as pure-tone average threshold > 25 decibel hearing level. Participants with methylmalonic acid (MMA) > 271 nmol/L at baseline received 1,000 g/d, and those with MMA < or = 271 nmol/L were randomly assigned to receive 0, 25, or 100 microg/d of B12. In a series of logistic regression analyses, compared with participants with normal hearing, those with impaired hearing had a significantly higher serum mean MMA concentrations in the best and the worst ears and a higher prevalence of elevated MMA (> 271 nmol/L) in the worst ear only. Thus, elevated MMA concentration may be associated with hearing loss in older adults. However, short-term B12 supplementation was unrelated to improvements in hearing status in B12-deficient individuals.

Could the fact that hearing loss is only associated with poor B12 status in some studies - combined with that conclusion that "elevated MMA concentration may be associated with hearing loss in older adult" possibly indicate that, at least for some medical conditions, it's not the B12 level itself that's important, but the MMA level? MMA levels can be influenced in various ways - not only with B12 supplementation.