B12 question

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B12 question

Postby SIE » Wed Apr 12, 2023 5:51 pm

Hi, Jeff,

Got a question today that is making my head hurt a bit... it looks like safe B12 supplementation is even more complex...

(I've searched the forum using the tools and no answers returned for B12 - so I apologize if this is already answered, couldn't find it.)

I was reviewing Dr. Tom Campbell's article on B12 when I saw his 2018 update:
https://nutritionstudies.org/12-questio ... tamin-b12/

"Update on 5/10/18: ... Recently, there has been some evidence that large dose B12 supplementation may be associated with an increase in cancer risk in some groups. *Because of these findings, and because I can’t find plain B12 supplements smaller than 500 mcg per pill, I’ve been recommending people take a multivitamin."

Dr. Tom references this study: Brasky, T. M., et al. (2017). “Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort.” J Clin Oncol: JCO2017727735.

See it at: https://ascopubs.org/doi/full/10.1200/JCO.2017.72.7735

Apparently the implications of high daily B12 supplementation are an increased risk of up to nearly 2x for lung cancer assuming high blood levels of B12. As far as I could make out the proposed causative mechanism, it appears related to interference with the DNA proof reading mechanism through involvement with methionine and homocysteine interactions. The study was arranged such that those taking a daily multivitamin would be in the lowest quartile, thus they were not found to be at risk.

Accordingly Dr. Tom recommended a multivitamin. This flies in the face of Dr. McDougall and T. Colin Campbell's recommendations to avoid multivitamins and other such sources of single concentrated nutrients.

Dad says - "Avoid synthetic isolated nutrients like vitamin pills" - son says "take a multivitamin"..... Oy, vey...

I'm not in a hurry to consume a multivitamin to get B12 - given the fact that most are loaded with isolated vitamins A and E, as well as synthetic folic acid - all implicated in studies of cancer and condemned by Campbell, Dr. McD, and others, in that order...

The 2017 study in itself has issues - would be nice if they tried this on a WFPB population, why such different results in different parts of the world, would be nice to boldly separate B6, 9 and 12 effects, and so forth.

Anyway, finally on to the questions:

I was under the impression that there was a severe limit to the amount of bioavailable B12 due to a limited supply of intrinsic factor. Thus my understanding was if one consumed 5000ug of B12, perhaps 15-25ug might make it to the bloodstream. Being water soluble to boot, any B12 that isn't stored shortly gets removed by the kidneys, no? (Otherwise, one 5000ug every few years would do it...)

Thus - with so little B12 making it to the target, how do the people in the studies sustain such a chronic high B12 level in the bloodstream for 10 years? Is this a study of a bunch of people trying to kill themselves by simultaneous dietary and supplemental B12 overdose? Does this only apply to people with an already maximum amount of stored B12? Disease of excess, B12...?

Would appreciate insight here - to say the least.

Finally - it doesn't follow in my mind that if the high dose B12 on the market is problematic we should therefore eat a vitamin pill every day for the rest of our lives just to get in 10-20ug of B12 - that after all might or might not be there - no oversight on these pills. It's relatively easy to get a 100ug B12 and either cut it in 4 parts or take one twice a week - IF that means it supplies the needed 2.5ig usable B12... does it?? Or how much is enough???

We're told the larger doses can be absorbed to a certain extent even in the absence of a healthy amount of intrinsic factor.
We're told that getting 15-25ug into the bloodstream is par for the course for 2500-5000ug taken orally.

If we need 2.5ug a day, that seems to demand popping 5000ug about once a week to be safe? (15/2.5=6)

What's the right way to do this?
SIE
 
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Re: B12 question

Postby Cihong » Wed Apr 12, 2023 8:38 pm

Not only does the vitamin B12 in multivitamins become unavailable because it forms analogues, but those compounds it forms can be harmful: https://www.ncbi.nlm.nih.gov/labs/pmc/a ... PMC370297/
Cut the C.R.A.P. (Calorie-Rich and Processed) and Get a Life! :) viewtopic.php?f=22&t=57638

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Re: B12 question

Postby SIE » Thu Apr 13, 2023 1:38 pm

The study also mentions that animals in developed countries are being fed increasingly synthetic feedstuff - and so as time progresses everyone will be getting less B12. This makes the whole issue more pressing...
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Re: B12 question

Postby SIE » Tue Apr 18, 2023 2:51 pm

Still more "fun" coming from further research...

Dr. Greger's said at times - take either 2500ug once a week, or 500ug daily, or get 25% of your requirements 3x a day from fortified foods...

Huh??? Even allowing for different absorption rates of different dosages this makes no sense.

How do you reconcile 500ug supplement pill a day with a three hits of 25% a day, i.e. less than needed at about 2ug, with being ok for daily dose? That's a dosage span of 250:1

If 2ug is enough, why take 500ug, and if 500ug a day is needed, 2ug is a joke even if split over 3...

The UK for their part think 2.5ug is a good daily dose - at least according to the labels on their multi's - and it seems sane... but... ??
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Re: B12 question

Postby JeffN » Tue Apr 18, 2023 2:59 pm

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Re: B12 question

Postby SIE » Sat Apr 22, 2023 3:27 pm

Thanks, Jeff

VERY much appreciated. I have no idea why I couldn't find those B12 references from the forum search tools...

Anyway, sometimes things go wrong with us - and B12 happened to win the cupie doll big time... and this thread started when I couldn't make heads nor tails of the Campbell's recommendations - but it is a real B12 issue I speak of, not a theoretical one.

We got into it innocently enough - Dr McD said anyone who ate the SAD had a 3 year supply of B12 - so we assumed what was chasing us after only our first year WFPB couldn't possibly be due to B12 deficiency... and further, in our foolish innocence, we figured even one B12 supplement of 5000ug would provide at least a thousand carefree days of happiness.... Not so, of course, due to absorption issues... The last straw is that we have a folic acid sensitivity in the family - so no enriched anything on the menu - which means no supplemental B12 in food, since they pretty much always add synthetic folic acid in food enrichment. Upshot - we came in low, misunderstood the absorption issue, and had no backup coming in from food.

Symptoms turned out to be (thankfully) a milder version of many of what happened here:

https://www.drmcdougallforums.com/viewtopic.php?f=1&t=47450&p=489153&_gl=1*ubkcdr*_ga*MTU0MzY1MjQ2NC4xNjgxMzM4NzY4*_ga_M3W192WV0Q*MTY4MjAzNDIzMC4xNy4xLjE2ODIwMzQyNTguMzIuMC4w#p502820

The missing parts of the discussion:

A. If you start WFPB already low on B12 It's going to manifest a LOT sooner than 3 years.
B. You're going to have to hit it fairly hard and regularly if you need to build up your stored B12 level from scratch.
C. Stored B12 is important, the principal insurance to cover a short term deficit.
D. Serum B12, Urine MMA and Homocysteine tests display evidence of actual deficiency.
E. Testing negative still gives no clue as to how much B12 is stored in the liver, i.e. how close you are to being deficient.

I have an idea that might fit all situations:

Intrinsic Factor is pretty much only a concern in the first 10ug of oral B12, and only a help in absorbing a limited amount. It's also somewhat random depending on digestion at any given time. Best to ignore it in calculations and go for direct absorption. The good news is give or take, the body still absorbs around 1.2% of supplemental B12 and in the grand scheme of things, it works well.

If you consume a maintenance dose, say 250 a day, 500 to 1000 twice a week, or 1500 to 2000 a week, that's all it is.

That maintenance dose leaves a weekly surplus of perhaps 10 micrograms, which isn't going to build up any great reserve any time soon if you happen to be deficient - more like it would take a few years to get from ground zero level to reserve half replenished. Okay if you happen to know your levels are fine, but maintenance doses are just that - maintenance.

Hence Dr. Greger's counsel for the deficient to consume 1000ug a day for 4 months to build up to normal levels, perhaps total reserve of 1.25 grams.

Sensible - if you consume 1000ug, about 12ug is absorbed, and 2 of that gets used that day, leaving about 10ug surplus times 120 days... coming from zero reserves, that's a couple year's cushion.

So - simplify this to the maintenance dose as cyancobolamin if all's well, and if not, do the deficiency level for a few months and then switch to maintenance dose. If (still) in doubt, test.

Perhaps just that simple.

-Mark
Last edited by SIE on Sun Apr 23, 2023 3:43 pm, edited 1 time in total.
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Re: B12 question

Postby JeffN » Sun Apr 23, 2023 6:55 am

SIE wrote:Thanks, Jeff

VERY much appreciated. I have no idea why I couldn't find those B12 references from the forum search tools...


:)

SIE wrote:So - simplify this to the maintenance dose as cyancobolamin if all's well, and if not, do the deficiency level for a few months and then switch to maintenance dose. If (still) in doubt, test.

Perhaps just that simple.


Correct. :)

Jeff
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