:::{| class="wikitable"
|-
!  !! Number !! Average serum B12  !! serum B12 < 203 !! MMA > .26 µmol/l  !! HCY > 15 µmol/l
|-
| Non-VegALacto-OvoB || 3627 || 216  || 46% || 70%  || 81%C
|}
A - Tended to eat only small amounts of animal products | B - 1 person was vegan | C - A low folate status could have contributed to the high HCY levels7 | HCY - homocysteine | MMA - methyl malonic acid

Iranian Villagers
Halstead et al. reported that some Iranian villagers with very little animal product intake (dairy once a week, meat once a month) had normal B12 levels. None had megaloblastic anemia. Their average B12 level was 411 pg/ml which was quite high considering their diet. The authors speculated this could be because their diets, which were very low in protein, allowed for B12-producing bacteria to ascend into the ileum where the B12 could be absorbed. They also speculated that because they lived among their farm animals and their living areas were littered with feces, they picked up enough B12 through contamination.

Halstead et al.'s 1960 report was in contrast to Wokes et al.'s 1955 report  in which numerous British vegans were found to have neurological symptoms of B12 deficiency.

Conclusion
B12 production by bacteria in the small intestine is possible. Some vegans can ward of overt vitamin B12 deficiency, and even mild B12 deficiency by remaining cautious. Now people like mihaiam may choose to doubt all these scientific findings hinging on their favourite anti-vegan blogs.

Note

I hope these information helps anybody who is interested.