B12-friendly lifestyle: How much B12 would be enough

As an experiment, let's say that you are exposed to ten different B12 reducing factors , each reducing the B12 levels with 1/3 of it's original value (33.333333%)

Let's you are told that you to consume as much as 3 mcg B12 daily.

1) 3 minus 33.333333% = 2 mcg
2) 2 minus 33.333333% = 1.333333 mcg
3) 1.333333 minus 33.333333% = 0.888888
4) 0.888888 minus 33.333333% = 0.592592
5) 0.592592 minus 33.33333% = 0.395061
6) 0.395061 minus 33.333333% = 0.263374
7) 0.263374 minus 33.333333% = 0.175583
8) 0.175583 minus 33.333333% = 0.117055
9) 0.117055 minus 33.333333% = 0.078037
10) 0.078037 minus 33% = 0.05205 mcg B12 daily

This is just an example. The numbers could be higher or lower. Maybe reducing by a certain amount of mcg instead of a percentage would be better. SOme of the B12-enemies might reduce B12 by 70% while others reduce only by 10%.

3.0 mcg daily intake is supposed to work for people who consume a diet high in sugar, fats, chemicals, tobacco, alcohols, medicine, coffee, tea, heavy metals from fish, vaccines and amalgam and bacterial overgrowth from meat. People on this diet often eat less fresh/organic food than healthy vegans, they a lot of processed/canned/microwaved/overcooked food.

Now, include acid rain, short period of breast feeding, chlorinated water, anti-biotics in meat and medicines and nutrient-depleted soil into this scenario....

If 3.0 mcg is sufficient for these people, people who are only exposed to a few or none of these B12-enemies should survive well on much, much lower levels.