B12

Updates:
See
https://qjmed.oxfordjournals.org/content/early/2013/02/27/qjmed.hct051
https://www.nlm.nih.gov/medlineplus/ency/article/003705.htm and
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3127504
https://www.vegsoc.org/info-hub/health-and-nutrition/vitamin-b12/

What is it? More ...
B12 is a generic term for a range of cobalamin molecules, thought to be essential for certain cell manufacture.

Where does it come form? More ...
B12 is produced by bacteria and archaea

How do I get it? More..
Mostly from food and maybe some from non-sterile environments.

Body Absorption and Storage

What use it it? and Blood Testing

What is it?

The various cobalamins supply a rare organic molecule containing Cobalt.

Termed a vitamin, any one of four species may be useful adenosylcobalamin, methylcobalamin, hydroxocobalamin and cyanocobalamin.

Where does it come from

Neither fungi, plants, nor animals are capable of producing vitamin B12. Only bacteria and archaea have the enzymes required for its synthesis, although many foods are a natural source of B12 because of bacterial symbiosis.
https://en.wikipedia.org/wiki/Vitamin_B12

Although all are produced by bacteria, cyanocobalamin is artificially manufactured due to its stability and hence economic value. Technically B12(cyano) is an artificial vitamer, a substance that the body can develop the true vitamin from.

It is far better to use B12(methyl) as a true vitamin, which also avoids the consumption of small amounts of cyanide, which in some cases can exacerbate other problems.

Luckily in the UK if someone wants an urgent intake this is often accessed via the NHS as an injection, who use B12(hydroxo), whereas in the USA B12(cyano) is standard.

However food supplements in the UK commonly use the B12(cyano)

Once essentialness of this is accepted there are a few considerations.

How accurate is information you use?
Do you consume enough?
Is what you consume absorbed?
Is that absorbed utilised in the essential manner?

The second and third item above are fairly easy to assess.

Consumption

Generally B12 is consumed as a part of a common diet. B12 is produced by bacteria and exists in the environment both externally and internally. Vegetarian animals such as deer may absorb most from the vegetation they eat as well as some small insects on the leaves.

Humans get negligible or no B12. from the vegetables and fruit they eat, assuming they eat much anyway, as most are grown in cidal conditions and those grown organically are often washed thoroughly. The bacteria that produce B12 does not grow inside vegetation.

Although B12 is produced in the human gut it is produced in the lower parts of the intestine from where it is not easily absorbed.

Which leaves us, humans, who don't eat our poo like rabbits do, to rely on eating the rabbits if we are inclined to.

Vegetarians eating dairy products, eggs and other animals bits they consider will do, may have greater consumption of B12, but there is a question of absorption within intestines so full of goo.

At least vegans who resort to B12 supplements will not have the same absorption problems a vegetarian may have.

The main foods that are supplemented are:

Yeast Extract
Soya milk

However for those who wish to supplement their diet finding a source of B12(methyl) would be preferable, even if that is to buy tablets.

Update 24th May 2014
Lactobacillus reuteri
https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2672.2008.04014.x/abstract;jsessionid=52AF6D8DB9FE1272CB383424033596E1.f04t04

Absorption

The UK recommended minimum consumption is about 3µg (microgramme) per day, with an assumed 50% absorption.

However if there is an absorption problem then taking higher amounts may not be the solution, especially if the supplement is B12(cyano) (Why? Less percentage is stored any side effects especially with the cyano)

The two possible absorption problems are a) too much food debris lining the intestinal wall, in which case a higher intake may enable some breakthrough or b) lacking something called 'the intrinsic factor' without which no B12 can be absorbed through common digestive processes. In the later case people will be advised to have an injection regularly.

Taking a B12 supplement containing ten micrograms or more daily provides a similar absorbed amount to consuming one microgram on three occasions through the day.
vegansociety.com/lifestyle/nutrition/b12

B12 Reserves

B12 is stored in the body so injections are not daily rituals. How much is stored from one injection is probably a matter of analysis after the event by testing blood levels of B12

Typical tablets may contain 100µg, Meridian yeast extract contains 3.5µg per 5g

If you have injections

a) have blood test to record level before each session so you can see how much is being absorbed. Do this at least 3 times before considering the following ... to be updated

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This entry was posted by elf and filed under Nutrients.

1 comment

Comment from: roger Member

The literature data on the acute toxicity profile of hydroxocobalamin show it is generally regarded as safe with local and systemic exposure. The ability of hydroxocobalamin to rapidly scavenge and detoxify cyanide by chelation has resulted in several acute animal and human studies using systemic hydroxocobalamin doses at suprapharmacological doses as high as 140 mg/kg to support its use as an intravenous (IV) treatment for cyanide exposure.[18][19] The US FDA at the end of 2006 approved the use hydroxocobalamin as an injection for the treatment of cyanide poisoning.
https://en.wikipedia.org/wiki/Hydroxocobalamin#Cyanide_poisoning

vow

B12