For humans, this means we need to get our B12 from an animal that does use microbes to make B12, such as cattle, sheep, and other sources of red meat and dairy products.
It isn’t as simple as just eating enough red meat. It needs to be the right kind of cobalamin (a generic name for the family of molecules that includes Vitamin B12 - essentially molecules with a cobalt ion in the centre (”cobal-”) and four amine rings in a square (”-amin”).
Notice how similar the name is to Vitamin (Vital for life - “Vita” and amine rings “amin”) - B12 may be the archetypal Vitamin too.
B12 has many important roles to play in the body, and one of these is to get rid of toxins. In the olden days of leaded petrol, there was a fair amount of lead in the air everyone breathed, and this would get into your blood. Even before this, we had lead water pipes and people were drinking lead in the water, and it got into people’s blood. Well, along came your ever-vigilant B12 and wrapped itself around the lead, carried it down to the kidneys, and escorted it out of the body.
B12 removes Lead, Arsenic, Cyanide, alcohol, tobacco toxic by-products, NO2 (nitrous oxide), anaesthesia used during surgical operations, an whole range of things that are bad for the body. And some medicines which work by being toxic too.
But there’s a down side. The down side is that when the B12 removes the toxin, it also removes itself.
People have puzzled why the symptoms of some poisoning looked very similar to B12 deficiency, or whether B12 deficiency produced symptoms similar to poisoning. But we have the answer, and some scientists have tested it and found it to be true.
When you smoke too much, one effect is that you create B12 deficiency because all of your body stores of B12 are used up getting rid of the nicotine and other toxic tobacco by-products. Because you have less B12 in your blood and in your body (and this has been verified), you also show signs of B12 deficiency because you also HAVE B12 deficiency. It’s possible to make some difference with B12 supplements, and it will reduce the awful feeling of a hangover (or the hangover you get after general anaesthetic), but don’t think that solves the problem really.
So just because you are taking lots of Vitamin B12 supplements, you still need a healthy lifestyle with good food, healthy exercise, rest, and avoiding toxic substances. Sorry, we can’t sort everything out with B12 supplements.