I usually inhabit the Thyroid UK community on HU - and have suggested to several people that they should post here as we see so many B12 issues.
We see people with relatively low B12 levels who seem to improve on high dose oral B12 (e.g. 1000 mcg methylcobalamin) - though some do get at least some shots. But when they try oral B12 there seems little guidance on whether to take it with food - or away from food. My thoughts are:
o... Even if someone is trying to go down the sub-lingual route, a fair proportion of the B12 will likely be swallowed;
o... The absorption of B12 using high-dose oral sources depends upon achieving a high concentration of B12 in the gut;
o... You will get a higher concentration if the B12 is taken well away from food.
So I am inclined to think it best to take well away from food. But in so many situations what seems likely,or even plain-as-a-pikestaff-obvious, actually isn't. And I have not managed to locate any research into this question.
So with food? Or well away from food?