B12 - How much is too much?
 

My latest blood test showed my B12 at 870. Should I discontinue taking 5,000mg of Methyl B12 or do it every other day?

I read some articles online that claim TOO MUCH B12 can cause blood clots and other problems.

Vitamin B12 and Folate: 870 (range 211-946)
Folate (folic acid), serum: 9.3

A level of 870--
 

--is not very high at all, especially for people who are supplementing.

Did you stop taking your B12 several days before the test was done? That might have given a somewhat more accurate reading; if you were still supplementing right up to the day of the blood test, chances are your B12 had been low for a while. Those of us who supplement with 1000-5000mcg of B12 daily often show much higher levels (my last one was in the 1700's); we often have to explain to not-so-savvy doctors why the levels are that high (and why it's OK--we're supplementing, especially as there are no known toxic levels of B12, with studies from Japan and Europe having given up to 36,000mcg daily with few side effects beyond a little hyperness of energy state).

Mr.s D can probably speak to this better than I can--I can say I haven't heard about high levels of B12 causing blood clots, though. I believe that there are some conditions in which both high B12 and blood clots may be correlated, but some underlying factor is resulting in both.

Can you link to the article that high B12 causes blood clots?
Was it Livestrong? That site is often spotty in its information.

It is important to watch for odd internet sites...that do not have scientific bibliography to corroborate their statements.

This is an example of one that provides a good bibliography:
http://lpi.oregonstate.edu/infocente...ns/vitaminB12/

and:

http://ods.od.nih.gov/factsheets/Vit...hProfessional/

Also a search on PubMed brought up no papers indicating clotting risk.

I did find on Mayo's site... a warning for people with cardiac stents. Because B12 may increase blood cell production, people with stents are to not use really high doses so as not to thicken the blood. The same goes for those with the genetic disease polycythemia Vera, which causes thickened blood with too many red cells. These are special situations, however. A simple CBC will show if there are too many red cells. Just about everyone here has had that test.

Yes, I believe it was Livestrong.

What do you think is a good B12 blood level? 900? 1,000?

Most of us with neuro symptoms keep our level above 1000.
Some more than others.

Going really high is not necessary unless some people have the rare transcobalamin problem. When this is low, transport of B12 is less efficient and it is thought then to keep the blood level higher, to make up for that loss. But the days are early for transcobalamin decisions, so I can't say with certainty yet, since everyone IS different genetically. Tests for transcobalamin are just beginning to be offered.

How long does B12 stay in ones system? If one stopped taking B12, how long before their levels would start depleting and is there a rate of depletion or is that dependent on the person?

Alot is dependent on the person.

The liver stores excess B12 up to 5 yrs, that we know of. Not everyone will have that long storage..but some do.

The reason I think it is important to stay over 1000, is the transport into the CSF (cerebrospinal fluid). B12 moves into the spinal cord and brain this way...involving a gradient from high (blood serum) to low (brain + spinal cord)... A person on TBI once posted a paper on this movement, and I wish I had copied it, but I didn't.

So the higher the serum the better the movement into the central nervous system. We know from recent studies that MS and Fibro patients show lower than normal B12 in the CSF taken by lumbar punctures. And also Dr. Snow in his very important paper had patients who he thought were fairly normal in levels, who did better on supplement ANYWAY. These were few compared to the total number, but still had neuro symptoms at fairly mid range B12 levels. So his take was to give the supplements anyway. I have that paper linked on the B12 thread. I think it is post #70.

So it will vary from person to person. But expect some B12 to be stored in the liver, and also to move into the CNS and out of the serum. After months of highs, that you feel better finally and stabilized there, you can drop to 1000mcg a day orally.

There also may be other factors... low D.... impaired B1 metabolism, etc. So once there is no change with B12, you need to look at other things too. Some PN tingling etc is paresthesia...a symptom of some imbalance. PN is a disease of nerves.(with damage). So separating that out is dicey and you have to be patient with those thoughts. Keep a journal, as that may help. Things like MSG in food will definitely cause neuro symptoms in some people. Glutamate and aspartate (Nutrasweet) are big culprits! Watch for those food intolerances ..that come from nightshades, etc.

On average, what daily amount of Methyl B12 will keep the level above 1000? Once I have taken a starting level, I can have my B12 level tested and go from there. I assume a 90 day period will be sufficient for a beginning test?

Thank you.

Mike

I think it depends on how low you were to begin with.

Some people are running only on liver stores. Others are absorbing some but not ideal amounts from food.

The body will want to use the B12 in whatever priority it seems to have. Some will get stored back up in the liver. Some will pass thru the blood brain barrier into the brain and spinal cord, some will go to the bone marrow for making new red blood cells, and then other tissues will get some too. I don't think anyone has discovered the priority issues, or tested them. But like every thing else, we are all unique and will respond the way the systems determine inside of us.

I think 3 months at 5mg a day, is enough to show if things are working well. If you stop the B12 for about 3-7 days, the last dose orally will be soaked up and the blood level will reflect what you need. If you test really high that may show your systems are "full" and the excess is floating around waiting to be excreted. If you are not really high (over 1000), then you are still repairing what needed it most (or you are not absorbing it properly).

My doctor said that high doses of methyl B12 (5,000 MG) can actually lower your B6 levels. So they recommended taking B6 along with B12.

Is this true?