How to absorb 2.4µg (or around) of B12 per day using supplements ?

[raphaelh42]

Hello, do you know how to absorb 2.4µg (or around) of B12 per day using supplements ?

I read 2.4µg is the recommended daily amount, I notice almost all B12 pills contains 1000µg and they say to take one pill/day

I struggle finding why they contain 1000µg instead of 2.4µg, I read it could be because it is easier to put 1000, I don't understand why monster energy drinks are able to put 2.5µg of b12 in 100ml, do you ?

I also read that your body absorb 10µg of a 500µg pill, I read it's because the body don't absorb the unneeded amount, so the body would absorb 10µg of a 10µg pill ? same for a 1000µg pill ?

Something is strange ! Or did I miss something ?

Edited August 2, 2022 by raphaelh42

[CharonY]

A couple of things here. Generally, if you are not B12 deficient (i.e. have enough dietary sources), supplements won't do you much good. Another thing to consider is bioavailability, as generally speaking you only absorb a fraction of anything you ingest. Bioavailability is non-linear, and the higher concentration your given source is, the smaller the percentage becomes that you absorb.  So for example if you take in 1 ug, you might absorb 0.5ug, while at, say 1,000 ug you might only get 10ug out. It is not about whether it is needed or not, but rather it is limited to what your body can take up in a given time frame from a given source (from certain foodstuff bioavailability is higher than for others).

So why do folks making supplements put such high concentrations in? There are two reasons. One is marketing, a higher concentration might make you feel you are getting more bang for the buck (and in energy drinks they are entirely a gimmick with no benefits). The other relates to my previous comment. If your diet provides you with enough B12, you are literally pissing away your money (and vitamins). 

However, if you are in even mild deficit (as in your B12 levels are on the low end) you need to fill up your supplies and you need to consume more than you lose to get back to the desired levels. If they are really low, taking supplements won't be enough and you need injections to get your levels back up. But again, without being diagnosed with low B12 levels, supplements are not helpful.

 

 

[raphaelh42]

I thank you very much for your response, I think it is getting more clear for me now, I'm interested about B12 because I don't eat food coming from animals anymore and I understood that I should then take B12 (I read animals don't produce it but some bacteria does and farmed animals get B12 from water/supplements/injections...)

If I understand, to know how much B12 I should take, I should do blood analyzes and compare them over time ? And if I know how much I need, how to know the base quantity needed to get the final result quantity that will get absorbed ?

Doing an internet research, it looks that people in my case just simply need to take one pill of 1000µg /day and they are good to go...

I'm a bit lost...

Edited August 2, 2022 by raphaelh42

[CharonY]

Well, if you want to have absolute certainty, it certainly would be best to get tested regularly with a given diet and then check whether you see a decline of B12 levels over time. 

Assuming you have a vegan diet, you may be interested in this study:

Gilsing A et al. Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study. European Journal of Clinical Nutrition 2010;64: 933–939

How much you need to take for prophylaxis is probably best guided by your serum levels and some discussions with your health care provider. Generally speaking B12 has low risk of overdosing, so having a regular intake of supplements generally should not have any issues, but again, it should best be discussed with your physician.

 

[raphaelh42]

Ok I think I will try to get tested regularly and try to find a health care provider/physician.

I have read the abstract part of the study, I don't understand everything but I will continue learning.

For the moment I will maybe take halves of 1000µg pills daily.

Thanks again, a lot.