b12

b12

my suggestion is 5mcg, 200% DRI as methylcobalamin

I like methylcobalamin but would prefer a considerably higher dose.

I like methylcobalamin but would prefer a considerably higher dose.

whats your reasoning?

I like methylcobalamin but would prefer a considerably higher dose.

whats your reasoning?

One is that many people has lost the ability to take up low doses of B12 with age and absorb around 1%. So at least 250 mcg would be required.

I like methylcobalamin but would prefer a considerably higher dose.

whats your reasoning?

B12 is notoriously difficult to absorb as Blue mentioned. Higher B12 intakes are associated with a slower rate of cognitive decline and larger brain volume. Exceptionally safe and non-toxic even in mega-doses (which I am not suggesting).

You will notice that Ortho-Core and Multi-basics include 647mcg, while they tend to be very conservative with the other B vitamins.

Edited by FunkOdyssey, 01 November 2009 - 03:56 PM.

B12 is notoriously difficult to absorb as Blue mentioned. Higher B12 intakes are associated with a slower rate of cognitive decline and larger brain volume. Exceptionally safe and non-toxic even in mega-doses (which I am not suggesting).

You will notice that Ortho-Core and Multi-basics include 647mcg, while they tend to be very conservative with the other B vitamins.

you agree with the 250 mcg dose blue suggested?

That sounds reasonable, I'd like to see if we could come up with something less arbitrary though.

1-3% is b12 is absorbed through passive diffusion...so from what i read 500mg-1000mg of cyanocobalamin will be absorbed in significant amounts even in people lacking intrinsic factor.

its possible methylcobalamin may not need intrinsic factor at all but i cant find any studies to confirm that...

i think 100mcg would be best...as with even a complete lack of intrinsic factor you would still absorb ~2mcg. most of us would be absorbing significantly more.

i think 100mcg would be best...as with even a complete lack of intrinsic factor you would still absorb ~2mcg. most of us would be absorbing significantly more.

I also here the RDA on b12 might be a little shoddy, but I'm going to need to look into that more. For some reason, there's a crowd that tries to get at least 2mg total a day. There's probably a good reason for that.

Still, extra b12 is easy enough to get from dedicated supplements. Your dose, while a little low seeming, is decent, especially if it keeps costs low.

As for forms... Meythl b12 gets talked up alot, but if it saves us a considerable amount of money, look into dibencozide (aka Adenosylcobalamin). Absorption is a little lower (not much), but it may cut costs, or provide additional benefits (shrug).

Vote is, of course, a yes on b12.

1-3% is b12 is absorbed through passive diffusion...so from what i read 500mg-1000mg of cyanocobalamin will be absorbed in significant amounts even in people lacking intrinsic factor.

its possible methylcobalamin may not need intrinsic factor at all but i cant find any studies to confirm that...

It doesn't need intrinsic factor. It is not a cyanide based form that in large dose has the potnetial to be toxic and needs to be converted to hydro- food -based form. Methyl-cobalamin is the coenzymated form, and doesn't require activation or conversion.

Beyond that doses in studies ranging from 5-30mg is where the fun stuff is seen, protecting and improving neural conduction and many neurological conditions.

The form is right, the dose is waaaaaaaaay off for me. That said, its 3500-4000/kg. So to dose high, where you get a nootropic effect, etc. its expensive.

AOR makes a 15mg methylcobalamin. NOW makes a 5mg sublingual of the methyl- form.

dibencozide/adenosyl is mentioned in the last post and is another coenzyme form, but has limited purpose in the body directly. Its worth including for completion's sake, but its utilized in the krebs cycle pathway. Methylcobalamin has awesome clinical potential for neurological protection throughout the brain/neural network and is far more exciting in terms of life extension. This is why the life extension companies talk up MB12 and dibencozide is an outdated sports nutrition supplement.

If I had to pick the choice is obvious. To have both, would be nice.

You're a true wordsmith ajnast4r...

Um, I respectfully have to say that none of you knows what you are talking about regarding B12 (except that the forms to take are methyl and adenosylcobalamine). All forms of B12 need intrinsic factor...some tiny percent can be absorbed w/o intrinsic factor, probably less than 1%. The dose you need to be effective is way higher than you list -- -- I take methylcobalamine 3500 mcg/day sublingual and it has to be JARROW brand or something equivalent. WHAT would be equivalent?? Any brand that takes a very, very, very slow time to melt -- like 45 minutes. The longer it is in contact with the mouth tissues and not slurped down the digestive tract, the more B12 absorbed. A brand that disintegrates in a few minutes or seconds is not effective.

This is from the people who actually have been diagnosed with B12 deficiencies, who take B12 by injection, and use sublinguals to maintain their levels inbetween injections. They say that even a 3500 mcg brand of methylcobalamine, if not retained in the mouth for close to 45 minutes (impossible with most fall apart brands) all their symptoms return. So this is how it works in real life with real people. The people who have the most experience to share on B12 are at this bulletin board:

www.wrongdiagnosis.org at the "Could it be B12?" bulletin board.

B12 is part of the methyl cycle and one of the pathways which, when it breaks, causes high homocysteine, which I have, and which is why I am careful with B12. You can read a lot of things in studies but to really make them work in a real person is an order of magnitude harder. Because if it works in 60% of everyone else, but not in YOU, well that's what matters, isn't it?

B12 is part of the methyl cycle and one of the pathways which, when it breaks, causes high homocysteine, which I have, and which is why I am careful with B12. You can read a lot of things in studies but to really make them work in a real person is an order of magnitude harder. Because if it works in 60% of everyone else, but not in YOU, well that's what matters, isn't it?

Madanthony, I would posit that you are an unusual case. This is a multi that is designed to supplement the vast majority of people who have normal absorption and metabolism as far as this vitamin is concerned. People who have an unusual medical condition need to treat it appropriately, but a multivitamin is not medicine for them. For what it's worth, the dosage and chemical form of the components of the multi have been finalized, and are not going to be changed until such time as a second batch is manufactured.

Swan Song

I don't know how to start my own topic so I'll put this here and let the moderator move it.
I have different interests so I'll be moving on to hang out at different places on the net.
But I want to leave you with this to consider:

As with most people who are under 30, most of you think you will live forever because of some studies on genes and such.

But most of you, despite what you think now, will get serious debilitating diseases as soon as your hormones wane.
The major part of living forever is avoiding the common diseases. Almost everyone in the U.S. gets high blood pressure once their hormones wane, for instance, and most drugs do not treat endothelial dysfunction so if you treat wth drugs you will be forever tired,
and treating with diet is by no means easy as the many studies would make it seem.

Most of you seem to think having high homocysteine is unusual and something that would never happen to you, but it is extremely common (it causes one of the most common forms of high blood pressure and is caused by the average American diet which is too low in B vitamins, or for some of us it is genetic).

If you have any of these extremely common problems now, you will have high blood pressure, high homocysteine, and heart and / or stroke problems later due to the broken methyl cycle you have today:
allergies
depression

Methylation is enhanced by estrogen. Probably one of the most important things you can study now to be prepared for later is how to do hormone replacement safely while avoiding cancer.

Men have it better since male andropause does not occur until between ages 60-70. On the other hand, men have it psychologically worse, because by then, when their health tanks, they ASSUME it's old age and don't recognize the part played by waning hormones. So be aware and look ahead.

Best wishes, all.

Of course, B12!--but I say 1 mg of methylcobalamin minimum! preferably more. And I wouldn't use the RDA as a point of reference for anything; these values were made as a bare minimum to prevent diseases resulting from a lack of the respective vitamin--they are very low...and since our purpose is to provide optimum health, the FDA has nothing absolutely to do with it.