Here's the short answer...

Mercury inhibits an enzyme which methylates B-12. Without memethylcobalamin (methylated B-12), your homocysteine levels rise and glutathione production is inhibited.

Elevated homocysteine causes heart disease, high cholesterol, and many claim is causes brain fog and fatigue.

Glutathione is the body's natural defense mechanism against heavy metals (which is ironically blocked by mercury).

Unfortunately, B-12 is involved in the methylation of mercury which essentially makes it able to pass through cell walls (bad).

So...

B-12 is a catch-22. You may benefit from it but it enables mercury transport in the body.

Solution?

If you are able to have homocysteine levels checked, and if they are high, or you are able to get your cholesterol levels checked and they are high, you may want to supplement with a premethylated form of B-12 a little to get your homocysteine and/or cholesterol levels under control.

If you're not able to get these things checked, you may have to rely on how you feel to determine if B-12 will help you.

In short: I would not use B-12 as a detox agent. I would only use it to buffer the effects of mercury toxicity or mercury detox if you need to. If it makes you feel better, it's probably helping to solve a problem you have.

If you want to raise glutathione levels in the body—not a bad idea if you're detoxing mercury—you can use N-Acetyl Cysteine. Start slow and always use Algin with it.

Hope this helps.