Transcript: Cheapest Source of Vitamin B12
The cheapest way to get our B12 is probably one 2500 microgram sublingual, chewable, or liquid supplement of cyanocobalamin once a week. The stuff is dirt cheap. You can find a twenty-year supply online for $40. All the B12 our body needs for $2 a year! Of course, the stuff doesn't last twenty years. It has a four-year expiration date, so share it with some friends.
For those mathematically-minded who are thinking, wait a sec. If you only need 4 to 7 micrograms a day, why do you have to take 2500 a week? Well, it's a little complicated, but let's do it. Our B12 receptors become saturated at as little as 1.5 . So we can only absorb 1.5 at a time through our receptor system. But about 1% of the rest passively diffuses right through our gut into our bloodstream.
So, for those of you into this kind of thing, let's do the math. When we take a 2500 microgram dose, we absorb 1.5 through our receptor system, and then 1% of the 2498.5 that's left. So inside our body we now have 1.5 plus that 1%. That comes out to be about 26.5. You do that once a week and that averages to about 4 micrograms a day. So, we should take at least 2500 micrograms once a week. We could take 3000 a week; 5000... If you take too much, all you get is expensive pee. And at a couple of bucks a year, it's not even that expensive.
Even though it is a water-soluble vitamin, we don't have to take it every day, because throughout our evolution our bodies were so used to getting such tiny amounts (maybe some wooly mammoth pooped upstream or something) that our body evolved an ingenious way to hold onto it. So that's why we can do this kind of averaging over time.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is transcript contributed by Bruce A. Hamilton.