cruiser

Vitamin B12 comes in different forms.

adenoxylcobalamin
methylcobalamin
hydroxocobalamin
cyanocobalamin

Cyanocobalamin is toxic. It releases cyanide into your body, and
poisons you over time.

I'm using cyanocobalamin and will stop immendiately. I need to get
either adenoxylcobalamin, methylcobalamin, or hydroxocobalamin.

I will have to look around.

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http://www.strokedoctor.com/vitamin_b12.htm

Cyanocobalamin is not biologically active until converted to
methylcobalamin, which also means releasing its cyanide. Cyanide can be
toxic because it binds the iron (F3+) portion of cytochrome oxidases,
preventing its reduction. This binding blocks electron transport and
interrupts cellular respiration. Symptoms of sublethal cyanide toxicity
include hypotension, tachypnea, and tachycardia.(4)

Cobalamin can bind with cyanide and is therefore effective in reducing
cyanide toxicity. However cyanocobalamin is not effective in removing
cyanide because the cobalamin is already bound. (3) Since nitroprusside
can induce cyanide toxicity, other cobalamins such as hydroxocobalamin
should be used to bind with cyanide. Nitroprusside therapies should be
minimized in critically ill patients and those with liver or kidney
dysfunction.

Large amounts of cyanocobalamin can exacerbate preexisting cyanide
toxicity that can result from smoking tobacco, sodium nitroprusside
therapy, and phagocytosis. Steve Roach, M.D. writes that "it seems wise
to avoid a potentially harmful form of a drug when the more physiologic
variety is available and is excreted at a more desirable rate.(7)

Foods fortified with vitamin B12 (as cyanocobalamin) may be a potential
problem if cooked. The highest mutation activity in cooked (pyrolysate)
vitamins was found in cyanocobalamin (3220 revertants at .025 mumole of
cyanocobalamin).(5)

In a comparison of cobalamins against cancer, adenoxylcobalamin was
effective against fast-growing malignant cells. Methylcobalamin was
effective at elevated concentrations and cyanocobalamin had no effect in
slowing the growth of any of the tumor cell lines studied.(6) In studies
that show that vitamin B12 has no effect on cancer growth, we need to
look closer at whether cyanocobalamin was used instead of the natural
coenzyme forms (adenoxylcobalamin and methylcobalamin).

Methylcobalamin enhances synaptic transmission in learning and memory.
Ikeuchi and associates studied the effects of methyl-B12 on the
electrical activity in hippocampal neurons and found that methyl-B12
increased post-synaptic field potential which lasted more than an hour
and increased the electrical currents elicited by N-methyl-D-aspartate
(NMDA). Cyanocobalamin had no effect.(13)

Methylcobalamin plays a role in modulating human circadian rhythms. It
accelerates re-entrainment of the activity rhythm to the environmental
light-dark cycle. The suprachiasmatic nucleus (SCN) is involved in
relaying photic information to the pineal gland. Methylcobalamin
enhanced the field potential in the SCN that lasted an hour. In
contrast, cyanocobalamin showed no effect.(16) Methylcobalamin is also
required in donating a methyl group for the synthesis of melatonin.
Methylcobalamin supplementation can assist in modulating melatonin
secretion, enhancing light-sensitivity, normalizing circadian rhythms
and improving sleep-wake cycles. (17) Methylcobalamin also helps improve
heart rate variability, suggesting that it is involved in balancing
sympathetic and parasympathetic nervous system function,(18) perhaps
through its involvement with light entrainment and melatonin synthesis.
Since circadian rhythm and melatonin synthesis are key factors in health
maintenance, the use of cyanocobalamin rather than methylcobalamin is
undermining our health as individuals as well as a nation.

Another study found a correlation between serum vitamin B12 in women and
their breast milk. When a group of lactating women were injected with
cyanocobalamin, there was also an increase of cyanocobalamin in their
breast milk.

As early as 1970, Dr. A.G. Freeman protested against the use of


British Committee on Safety of Drugs. Dr. Freeman voiced the concern
that even if hydroxocobalamin is prescribed, cyanocobalamin is
administered in its place. They wrote that "because doctors are still
confused about the differences between various forms of vitamin B12
commercially available and about their possible adverse effects,
manufacturers should withdraw cyanocobalamin in favor of
hydroxocobalamin for therapeutic use." (8)

A letter from Dr. Terry was published in the October, 1978 issue of The
Lancet. He wrote that "the lead for improved prescribing must come form
compilers of formularies that are highly regarded. In this respect it is
disappointing to find that the W.H.O. expert committee on the selection
of essentiald rugs lists only cyanocobalamin, placing an incalculable
number of patients with optic neuropathy in pernicious anemia or tobacco
and tropical amblyopia at risk." (9)

In the November 1978 issue, the Lancet published a letter by J.C.Linnell
and associates entitled "Therapeutic Misuse of Cyanocobalamin." The
authors state that cyanocobalamin itself has no known biochemical
function. Only trace amounts of cyanocobalmin are normally detectable in
the human body, while significant amounts occur in patients with optic
neuropathies, inborn errors of cobalamin metabolism and pernicious
anemia. Cyanocobalamin must first undergo conversion to the
physiological forms of cobalamin before being effective against
pernicious anemia. However hydroxocobalamin (a precursor to methyl and
andenoxylcobalamin) "has the additional advantage of therapeutic
efficacy in certain neuropathies and some cases of inborn errors of
cobalamin metabolism." The authors further write that "it is lamentable
that an extensive demand for cyanocobalamin as a therapeutic agent
should persist. There seems to be no place for the continued therapeutic
use of cyanocobalamin." (10)

Vitamin B12 is found in algae, peas, clover, alfalfa, mustard, egg yolk,
chedder cheese, sardines, herring, anchovies, calve's liver, haddock,
salmon, and cow's milk. Plants containing S-methylmethionine include
cabbage, kohlrabi, turnip, tomatoes, celery, leeks, garlic, beets,
raspberries and strawberries (14). Cyanocobalamin is in haddock and
cassava root. Elevated amounts of cyanocobalamin have been found in
smokers and cases of amyotrophic lateral sclerosis and optic atrophy.

Clinical doses of methylcobalamin are 1500-6000 mcg per day and can be
administered orally, intramuscularly or intravenously with positive
clinical results. Methylcobalamin is well tolerated and has no known
toxicity. B complex (riboflavin, folic acid, pyridoxine, and choline),
and zinc assist methylcobalamin effectiveness. It is important that
physicians giving injections check the source of their vitamin B12. Not
only can it be cyano rather than methylcobalamin, but the shot gun
approach of giving liver extract can include allergenics. One report
states that 10-30% of pharmaceutical preparations may be noncobalamin
analogues, that are either inactive or cause allergic reactions. (1)

In conclusion, methylcobalamin can be effective in cases of neuropathy,
depression, cancer, optic atrophy, heart rate variability,
homocysteinemia, and sleep disturbances. However, all cobalamin
analogues are not equal and taking cyanocobalamin with already elevated
levels of cyanide can actually be harmful. It has been thirty years
since Dr. Freeman first published a letter in The Lancet about the risks
of using cyanocobalamin. How much longer can we afford to allow
ignorance and profit motives to undermine our nation's health?
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Cruiser

cruiser

This may account for why previous attempts, by members of this group,
at using B12 and folic acid have not gone well.

Cruiser