To answer to Fosettes comment:
” Je mange végé sympa et on m’a dit que je risque de manquer de vitamine B 12″
which translates in “I’m vegetarian friendly and was warned about the possibility of B12 vitamin deficiency”.
A very good document for French readers can be found at “alliance vegétarienne“‘s website.
For lazy English readers here is a summary:
Who is concerned?
Pregnant and breast-feeding women, vegans.
Where do we found it?
This vitamin is created by bacteria in the soil or on animals.
This vitamin can be accidentally found on vegetables. You can find it mainly on animals as it is produced in their intestinal flora. We also produce (in our colon) some of this vitamin but they are not absorbed (it far too low…). The last option is through complements produced in the industry where they use bacteria strains. They add it to some food, as yeast (because the vitamin produced by yeast isn’t enough for human to absorb it).
Recommended daily amount:
< 1 year: 0,5 μg
1 – 5 years: 1 μg
5 -10 years: 1,5 μg
10-..years: 2 μg
Pregnancy and breast feeding: 3 μg
- One phial or ampoule of vitamin B12 Gerda 1 000 μg/4 ml every ten days (according to VIDAL)
- one pill every day of 10 µg of vitamin B12 (be careful some may contain lactose so are not suitable for vegan),
- this vitamin can be added to some food as yeast, cereals,…
Do you suffer vitamin B12 deficiency?
The only way to detect it is trough blood tests.
- below 100 pg/ml the deficiency is clear,
- above 400 pg/ml there is no deficiency,
- between 100 and 400 pg/ml more test should be done.
If you eat seaweeds, this could skew the results.
So vegetarians and vegetarian friendly shouldn’t (?) be concerned… Usually vegan are aware of this fact and take it into account therefore they rarely lack of this vitamin.
More on nutrition can be found on The vegetarian society.