Getting B12 from non-food sources
It seems that we're meant to actually eat/chew food, and not just swallow it. :-)
If we get our B12 from pills, we absorb less of the B12 in them than they contain if we just swallow the pills. (This is the reason why some people use sub-lingual B12 supplements).
Quote:
Chew or Dissolve Supplements Under the Tongue
Crane et al.6 (1994, USA) noted that tablets of one vitamin company dissolved slowly in water and acid. They then conducted a study to see if vegan patients who had not responded to oral B12 (described below) tablets swallowed whole could improve their B12 response by chewing the tablets. 7 people chewed the tablets of 100 µg (once a week for 6 weeks) and their average sB12 levels went from 116 to 291. Of the 9 who didn't chew, theirs increased from 123 to only 139. (However, a 100 µg dose once a week is not a lot of B12. The more surprising result of this experiment was the large increase in the sB12 of the 7 people who chewed the tablets, not the small increase of those who did not chew.)
7 of these 9 then chewed 500 µg/day for 10 days and their levels rose to normal with a final average of 524 +/- 235. Three participants could not raise their levels orally and required B12 injections to maintain sB12 above 300.
If you're doing well by swallowing B12 supplements, and not taking the sub-lingually, this means that whatever amount you take, you'd need less B12 to achieve the same absorption from food (or sub-lingual B12).
