---a 1000mcg Methylcobalamin B12 tablet would be just as effective as any of the "sprayed sublinguals", which are not really appreciably absorbed under the tongue anyway.

The minimum daily requirement for B12 is somewhere in the neighborhood of 2-10 mcg each day, depending on age and absoprtion factors. The reason for "megadosing" with 1000mcg each day, or higher, is so that even if one has lost all the parietal cells in the stomach, one will still passively absorb through the digestive tract somewhere around 1-2% of the dose (10-20mcg) and meet one's requirements that way, and even begin hopefully to replenish stores if one has been deficient for a while (the body will appreciate the extra for repair if needed).

Given that methylcobalamin is cheap and easy to find--I buy a 100 pack of 1000mcg through on-line vendors such as Swanson or iherb (depending on what else I'm ordering and what sales I can fold them in with) which lasts 3 months plus and costs about 8-9 dollars total. So it's a very easy and inexpensive insurance policy.

I'm actually partial to R-lipoic acid, the active R-isomer form of alpha lipoic acid, for it's blood sugar stabilizing and antioxidant effects--and because one can take much less of it for a roughly similar effect (about 50-100mg of R-lipoic translates roughly into 300-600mg of alpha lipoic in terms of efficacy for most people). Some people find the larger doses of alpha-lipoic acid, well, acidy, and taking the R-lipoic helps to mitigate this.

Remember to take the methylcobalamin on an empty stomach, at least an hour before and two hours after eating; the cobalamin molecule is the largest one our body regularly uses as a nutrient and as such it is easy to complex it or interfere with its absorption if other stuff is around to compete with it.