The words methylcobalamin, cyanocobalamin and B12 are everywhere in the health world at the moment, but what exactly are they? What do the complicated chemical names mean, and what effect do they have on you? Let’s find out…
Disclaimer: In an attempt to make sure everyone can understand this without a PhD in biochemistry, some of what follows is inevitably going to be slightly oversimplified. But I’ll make sure the basic principles involved are solid.
The Very Basics
At their most basic, vitamins are just a group of chemicals that every human needs to lead a healthy life. You only need tiny amounts of each vitamin, but they’re still absolutely vital for normal growth, metabolism and activity.
Scientists classify vitamins by splitting them into groups, one of which is known as the ‘B Vitamins’. All B-vitamins are water-soluble (i.e. they dissolve in water), and they’re essential for cell metabolism. This is basically the name given to a number of important chemical transformations that occur in every single cell of your body without you ever knowing.
As vitamin B12 (aka cobalamin) is one of these B vitamins, you would expect there to be at least twelve of them. However, that would make things too easy, and due to a historical quirk there are actually only eight.
B12 is the largest of all the vitamins, and also the most chemically complex. It contains a cobalt atom at its heart (hence the alternative name ‘cobalamin’), and it happens to be a nice deep red color. That’s all you really need to know.
Where Does Methylcobalamin Fit In?
It turns out that the term ‘vitamin B12’ can be broken down further. The name actually encompasses a small group of compounds that are extremely chemically similar, and all of them do the good work you’d expect a vitamin to do. These exceptionally similar compounds are known as ‘vitamers’.
Methylcobalamin is just one of these vitamers – the others are cyanocobalamin, hydroxocobalamin and adenosylcobalamin, all of which we’ll take a quick look at later. Don’t let the long chemical names put you off – they’re helpful to chemists, but otherwise they’re mostly just used to make scientists look clever.
Where Does Vitamin B12 Come From?
Humans can’t produce their own B12, and nor can any other plant, animal or fungus. Only bacteria have the ability to synthesize vitamin B12.
This means that we need to get all of our B12 from our diets, and all the B12 you’ve ever ingested was originally produced by a bacterium somewhere. Every animal has millions of bacteria living in and on them (a situation called ‘bacterial symbiosis‘), which is why we can find B12 in the food we eat. It also explains why animal products are especially rich in B12.
The Inconvenient Truth
Unfortunately bacteria can only produce hydroxocobalamin, one of the B12 vitamers we mentioned earlier. The problem is that this type of B12 isn’t actually of any use to us straight away.
Before we can reap the benefits of this essential vitamin, we have to convert the hydroxocobalamin into one of the so-called ‘active’ forms of B12. This is either methylcobalamin or adenosylcobalamin, which your body can then switch between whenever it needs to.
These two kinds of vitamin B12 are said to be highly ‘bioavailable’. All that means is that if you were to take pure adenosyl- or methylcobalamin, your body would be able to absorb it and use it straight away without any prior internal conversion.
What About Cyanocobalamin?
Well, you’re unlikely to find cyanocobalamin in the natural world. It is by and large an artificial, synthetic form of B12, produced in labs for the supplement industry.
The only difference between any of the vitamers is in one small group out of the whole large molecule. But it is significant here – your body can’t use cyanocobalamin, and has to convert it to methylcobalamin. This means swapping out that small group, from cyanide to a methyl group (just carbon and hydrogen).
Yep, cyanide. The well-known poison. When your body converts the cyanocobalamin in a B12 supplement to methylcobalamin, cyanide is released into your bloodstream.
Luckily there’s no need for alarm – there are actually quite a few common foods (e.g. apples and almonds) that release similarly small quantities of cyanide. It’s such a small amount that it shouldn’t do you any harm at all.
But this is nevertheless the primary motive behind the growing trend for switching to B12 supplements that use methylcobalamin. It seems fair enough that people don’t want any amount of poison entering their body from something marketed as a health product.
Why Does Anyone Make Cyanocobalamin?
Cyanocobalamin is still the most common form of vitamin B12 in dietary supplements, particularly in multivitamins and even more so when it’s used as a food additive.
Cyanocobalamin is cheaper for pharma companies to produce than the natural alternatives. It’s also a little easier to store, which also drives costs down further. Methylcobalamin is even thought to have a number of medical advantages over cyanocobalamin, but as ever, profit trumps all other concerns.
As you can probably guess from the name of the site, MethylcobalaminInfo.com is firmly in favor of methylcobalamin. We think it’s the logical choice for anyone who wants to make sure their body is given the best, rather than what yields the biggest profits for powerful businesses.
To help you out, we’ve compiled a list of some of the best B12 supplements that contain methylcobalamin – you can check the list out here.
And if you want help choosing which kind of supplement would be best for you, then we’ve got that covered as well – you can read our article on choosing a B12 supplement here.
The top image has been released into the Public Domain by its author. The second image is by Steven B. Harris, obtained through Wikimedia Commons under a CC BY-SA 3.0 license. Other images, from top to bottom, are courtesy of dream designs, m_bartosch, and Salvatore Vuono, all at www.freedigitalphotos.net.