Vitamin B12

My B12 level was 267 and according to one doctor that was considered "low".  She told me to take a B12 dosage of 200 mcg daily.  My regular doctor then saw me a couple of days later and stated he didn't consider it to be low.  I took the regualr b12 vitamin supplement for a month and noticed no difference.  Then as time went on, my symptoms were all still there (mental fogginess, sluggish memory, difficulty in concentrating etc).  With all the talk regarding "low" levels, one being normal is 200-900, another being 500-1100 I thought well maybe it can't hurt to just take the vitamin b12, however, take it in the sublingual form which I read absorbs better.  The only 2 doses I found on the market were 2500 mcg and 5000 mcg.  So today I started taking the one daily under the tongue 2500 mcg.  Can this hurt me?

[steve80]

I'm not an expert.
But you can read everywhere that what's too much of B12 your body just flushes out through the kidneys without trouble, even for very high doses. It's said, there aren't any reports of a dangerous dosage.
I just don't remember 100% if this was only true for cyanocobalamin, or for all forms.

Another thing: there are different methods of measuring if you have enough B12. Some of them are not reliable. Studies showed that some people developed severe B12 deficiency symptoms but the serum level if B12 being OK.
Did they also check your homocysteine level ? Too high levels indicate that something's wrong with your B12 intake.

If symptoms don't get better after some time (check with your doctor how long you should try) taking this high B12 doses,
I know of 2 reasons:
1) maybe it's something different than B12 causing trouble (or additionaly)
2) weak resorbtion of B12 (where either higher doses help, or, if resorbtion is really bad,  injections)


Ah, just found this nice site :-)

http://www.b12vitamin.com/