Take B12, sublingual -METHYLcobalamin.
At least 1000mcgs per day -
not along with any other vitamins or suppliments.
Its pleasant tasting and easy to take.
I take 2000-5000 per day.
I use Jarrow 1000mcg tablets & get it cheaply from iherb
when I buy 5-8 bottles along with my
CoQ10, ALA &, Omega 3-6-9 fish oil.
That way the shipping is spread out over many items-
esp if there's a special sale on.
They're fast, too.