Anyone can google any kind of nonsense and find plenty of results, be it alien abductions or adverse effects from B12. So what? The internet is full of hysterical nonsense and if there's anything less reliable then anecdotal evidence, it's anecdotal "evidence" posted by anonymous people on the internet. I'm pretty sure that the reports of adverse effects from B12 are entirely due to people experiencing placebo effects and obsessing about it.
The only legitimate ways to determine adverse effects are clinical trials and the observation of professional physicians. There have been countless trials with B12 and decades of clinical experience and yet no adverse effects have been found whatsoever. If you get a high dose prescription form of B12, the leaflet doesn't even list a single adverse effect.
Ah, and please spare me that methylation moonshine. Methylation seems a bit like quantum physics - people who don't have any background in physics/biochemics and no real understanding of the subject love to project all sorts of mumbo jumbo into it.
Yes, methylcobalamin is a methyl donor, it adds to the body's pool of methyl groups. Just like a drop of water adds to a swimming pool. I'm baffled how people put furth grandiose theories about how trace vitamins (B12 and folate) with attached methyl groups purportedly affect methylation without giving any thought to the scales involved. If you are really concerned that a single dose of methylcobalamin could affect your whole-body methylation status you may as well be concerned that pissing into the ocean might cause a flood in Bangladesh.
To give you a concrete example: one single egg would supply you with several thousand times the amount of methyl groups provided by a 1 mg dose of methylcobalamin.
"Methylation seems a bit like quantum physics"
LOL! It's just chemistry. Although you can probably say everything ultimately boils down to physics, but there can be no doubt that that was not your meaning.
"people who don't have any background in physics/biochemics and no real understanding of the subject love to project all sorts of mumbo jumbo into it."
That's true, there is all kinds of bullshit about methylation on the internet. Half of it is people blowing actual differences between cyanocobalamin and methylcobalamin way out of proportion. However I'm not one of those people considering the 3 years or so of chemistry, bio- and organic chemistry that is required for my major in evolutionary biology.
Also, your paragraph about methylation has little do with anything I said because I was never arguing all that nonsense. That's not where I was going. Especially considering that gross mischaracterization of my point with your argument about "a single dose of methylcobalamin." It doesn't pay to be that irrational and erect absurd straw men. Calm the fuck down. I only go by the facts and in this case it is a fact that a person can have three different sets of side effects for those three types of cobalamin. The different functional groups that the B12 is attached to DO alter the compound and DO have different effects in the body, however subtly. That's partly why they're called functional groups, remember?
If you think you can argue against this you're going to be in for a nasty surprise considering how many thousands of compounds we can list that we can alter the way the body uses them just by adding some a methyl group or two, a phenyl group, a carbonyl group, a hydroxyl group, etc to the compound. Sometimes these very tiny changes can incur massively different effects in the body, like changing a harmless, nearly inert compound into a lethal substance. Chemistry is pure sorcery like that.
And around these boards, all we really have to do to verify this fact is ask simple questions like these: What is the difference between piracetam and phenylpiracetam? What is the difference between GABA and phenibut?
Edited by Duchykins, 25 June 2015 - 08:19 PM.