PN= Peripheral Neuropathy
Posters on PD, MG, MS, RSD, Bipolar and other forums all use
methylB12 successfully here. If you think my posts are intense you
should read the PD (Parkinson's) forum where technical posts are
the norm.

I cannot help it if the information is "too intense". I water it down and simplify quite a bit for this format on NT.

I bolded the part of Dr. Snow's paper, pertinent to giving extra B12 for those who tested in the borderline low range. It is 2 sentences long. Reading outloud so that one can HEAR the words instead of seeing them, often helps. Having someone read the posts to them, may also help. Auditory functioning can be easier for people with cognitive problems, than visual sometimes.

I put links up for those who want to delve more deeply into a subject.
I also think the internet is not trustworthy and provide the links as proof of medical studies and medically acceptable content.

Many people may have to read some information more than once. Or in batches. I have to do that sometimes myself.

The link to my sticky on PN is in this thread.

I recently started taking 2500 mcg of B-12/day. Is this too high? Should I be cutting these tablets in half and taking them?

No. No need to change the dose. Only about 13 mcg gets absorbed ideally from 1000mcg dose. Ideally means taking it alone on an empty stomach and no food after for about an hour.

If you worry however, anyway, you can take it every other day.
But if you eat with it or near taking it ...don't count on much being absorbed.

Vit B12 has no upper limit of dosing.

Taking 2 of your GNC vitamins at a time, however may be problematic depending on the formula. Those are designed for one a day use unless the label says the formula is for 2 or more tablets at a time. (some vitamins get too large to swallow so they make them multiple dose in that case.)

mrsD,

Why do you need to take B-12 on an empty stomach is you can get it into the blood stream taking it before or after a meal ?

I take about 400 mcgs after breakfast and my blood levels are 970 pcgs/mL

My focus is keeping the continuity of taking it day after day so with half-life considerations, there is a continuous amount in the blood stream.

I have found that continuity is more important with all of the vitamins and supplements. My father was big on the timing and such but I would never get all of my regimen done if I had to space them out so much. Twice a day is enough for me.

Mrs D,

In some of my studies in the past I recall that supplementing B12 sublingually was a better avenue for absorption; does that hold true, or have the tablets/capsules been protective enough to protect their passage thru the Stomach acids now for later absorption in the GI tract?

Mark, you may have intact intrinsic factor functions.

There is a finite amount of intrinsic factor secreted in the stomach with food intake. It will enable absorption of B12 from food sources (which is about 1-2mcg/meal) when it works well.

The empty stomach for supplements is for PASSIVE absorption when intrinsic factor fails. It used to be thought that nothing could be absorbed without intrinsic factor activity but now that has been disproven.

With time and aging people develop low acid in the stomach. This is called achlorhydria. In fact in the early 20th century, pharmacies actually dispensed hydrochloric acid to be diluted in water, for this condition. Studies show about 30% of people 50 and over may have this lack of acid. When this happens naturally or because of using heartburn medicine too often and too much... the stomach cannot break up protein that contains the B12 properly, and so it does not attach to the instrinsic factor and is not absorbed, in the intestine.

Autoimmune issues/disease or hereditary genetic failures in the intrinsic factor production also occur. When this happens in younger people they cannot absorb B12 from food either.

Poor diet (vegan lifestyle or not eating protein)
Autoimmune disease
Chronic use of heartburn acid blocking drugs or metformin
Celiac disease or other malabsorption like Crohn's disease,etc

All will result in low B12 absorption.

The high dose supplements are designed to bypass intrinsic factor and when given very high like 1000mcg/day or more, a few micrograms will get passively absorbed into the body we know now. Presence of food will be a physical block to that process which is very delicate. B12 only gets in thru a short area of the small intestine. We know from studies that presence of food impairs microgram dependent drug absorption too.. Levothyroxine must be taken on an empty stomach, and so also for digoxin. Presence of fiberous food...like grains, bran, veggies, are the worst because the micrograms are lost in the fiber.

This table shows how much B12 was absorbed during a study under different conditions. The PA (pernicious anemia column illustrates the upper limit for intrinsic factor itself.).
http://www.ncbi.nlm.nih.gov/pmc/arti...able/T1/#TF1-4
you will see at 500mcg --your dose-- 9 mcg was measured in this study. This study, gave on an empty stomach. 9mcg is about twice the RDA for B12. So if you take yours daily every day, you will end up with good levels, over time.

Notice on that table link... that PA patients, who consumed 1000mcg B12 orally were almost equal to the non PA patients.
This demonstrates that at this high intake level, that PASSIVE absorption is working even in the pernicious anemia patients (who have no intrinsic factor). This is why oral supplements have to be high dose to work for EVERYONE.

Now this does not take into consideration those using cyano vs methyl. That is another problem. Cyano is not active biologically and if people have genetic DNA errors preventing methylation...then the cyano will not work in the body. This factor is separate from the intrinsic factor failures. It is only about a decade old, and was discovered as the genome was decoded. This is why I only recommend active Methyl B12...because we cannot see inside people to know what their genetic situation is.

This link gives a diagram on how B12 is broken down from protein, attached to intrinsic factor, and then absorbed in the intestine. This is a complex situation and even many doctors do not understand it. This link was made for doctors...for their CME (continuing education).
Figure 2.
http://www.aafp.org/afp/2003/0301/p979.html

Today methyl B12 is pennies a day. I just learned that Costco now offers it . It works out to 6 cents a tablet. Why use anything else, when this is so available and is the type the body actually uses?

Dr. Snow (whose link I gave you before also), mentions in his research that some people with fairly "normal" blood levels, of B12 still had neurological impairments, and giving a higher dose worked for them. His opinion is that some people just need more.
Now that may reflect an error in Transcobalamin transport, and that is rather new still, and tests are just coming out for that factor. Low levels in transporting it around the body, may be serious for some. In fact you could test high, and still not be getting B12 delivered to tissue sites. It is thought that low transcobalamin can be bypassed with mega dosing. And that this error is probably genetic also.

So Mark in your case, you might be lucky that you have the genes to handle B12 metabolism. But without an MMA test you really do not know if you are utilizing what is being measured.
You could just have lots of cyano floating around. So it would not cost you much to switch to methylcobalamin at this time, and use 1000mcg daily. 6 cents a day from Costco.
http://www.costco.com/webber-natural....11659799.html
and:
http://www.costco.com/.product.10002...rySiloedViewCP

Also Walgreen's is now offering methylcobalamin on their website and in some stores. The fact that this is FINALLY making its way to consumers is a very good thing!

Our bodies are very complicated. VERY. It is not really a matter of just taking a pill anymore.

MrsD,

NM, your answer to Mark above is what I was referring to, thanks........... not really the stomach acids per se.

Thanks again.

Can't tell you how many 'go rounds' I had with my Supervising Physicians in checking MMA and Homocysteine studies, along with B12, and folates, in the 80's-90's, before they finally started recognizing them as valid studies for anemias.

Thanks.

Yes, 1 serving of the GNC multivitamin is two pills. So I was going to take one with breakfast and one with lunch, and then take all my other vitamins with breakfast (D3, B-100 complex, fish oil). THe B-12 I am taking as soon as I wake up before I get into shower to allow some time before breakfast.