It depends on what the problem is you are trying to solve. Is it for mood or energy or homocysteine reduction or to compensate for say a diet that is vegetarian? Or is it for extreme neuropathy pain? The only version I used was the methyl version as I did not want to count on the liver being able to make the transistion from the cyanocobalamin form which is much cheaper and what you find in a pharmacy or even see listed in multi vitamins. The methyl version is what the liver will hopefully create out of the cyano form, so the methyl version is harder to source in a vial.

Look at this doctor's explanation:

http://www.dadamo.com/B2blogs/blogs/index.php/2004/01/16/cyanocobalamin-versus-methylcobalamin-1?blog=27

Since you say you're a tea drinker...here is one that I find definitely helps reduce blood sugar...Freshpak is the brand..South Africa's No 1 Rooibos tea. I purchased it in a health food store. Green tea helps but Rooibos has a more profound impact. I would add a splash of lemon juice from a bottle and a sweetener packet.

My GP who is not diabetic has a theory that artificial sweeteners cause weight gain but that must be only in people who have a system that can be tricked into releasing their own insulin because I have never found it to be true in me where I am the only one who can cause a weight gain by injecting more insulin. So I do have Sweet'n Low in the home for use when absolutely necessary for things that need improving...like some teas where I add lemon, or the greatest tea that I make from raw ginger that I also chew and eat when I want to counteract an infection....1 lb of raw ginger over 5 days will do that if all is fully eaten after 2 strong teas have first been made out of it.