50mcg Vitamin B12 supplements....

[Sarahlouise1980]

Is it true that 50mcg vitamin b12 tablets will raise levels as quickly as the high doses of vitamin b12 such as 1000mcg?

Thank you!

[Gambit62 Administrator]

Slightly off topic to discuss absorption in people without B12 absorption problems but

if you don't have an absorption problem then 1000mcg per day will is likely to be just as effective as 50mcg twice daily.

Most B12 is absorbed through specialised mechanisms in the ileum - averages 99% - with a smaller amount being absorbed 'passively' elsewhere in the gut. Though this seems to vary significantly from individual to individual and for some people passive absorption doesn't really work at all.

The capacity of the main mechanism or absorbing B12 is limited to somewhere around 10mcg per meal.

So, on average 1000mcg 1x a day will give you about the same as 50mcg 2x a day (taken with meals).

Daily requirement for B12 is 2.5-5mcg so you would be taking in significantly more than you needed.

Generally excess B12 is removed by the kidneys and the rate at which the B12 is removed is greater if the amount of excess B12 is greater - however rates vary a lot from one individual to another making it impossible to predict how any individual is actually going to respond to taking very large quantities of high dose oral (ie multiples of 1000mcg).

However, as stated in responses to your earlier post, it looks as if you do have a B12 absorption problem, meaning that neither of the two options is likely to be effective in raising B12 levels - certainly not going to be quick and you really would be better off having an injection to raise levels.

[Budsa]

The 50mcg tablets are usually prescribed for low B12 due to dietary insufficiency which normally only occurs with vegans. They are taken 3 times daily on an empty stomach.

1000 mcg should be sufficient if you have any type of absorption problem, unless you are suffering neurological symptoms or have a critically low B12 level. 1% of B12 is absorbed passively, anywhere between the mouth and the anus. This applies regardless of the reason for low B12 in blood serum.

Doctors in Canada and Sweden routinely prescribe oral B12 rather than IM injections for lifetime treatment of B12 deficiency.

frontiersin.org/articles/10...

[Sarahlouise1980 in reply to Budsa]

Thank you Budsa. I am trying the 1000mcg sublingual B12 x