Posted by Larry Hoover on February 22, 2007, at 15:24:32 [reposted on February 25, 2007, at 13:19:23 | original URL]
In reply to can you really hurt yourself with high vitamin B6?, posted by iforgotmypassword on February 22, 2007, at 13:31:39
> i am very interested in the akathisia studies on pubmed that used 1200mg/day. i am worried however, another pubmed study said that high B6 damaged rat brains (and wasn't actually super high per kg it seemed.) the term "nerve damage" is thrown around a lot in reference to B6 but then so is "reversible". what's the real story?
The neuropathy develops due to two factors, dose and duration. An acute treatment (say, a few weeks) at a high dose will likely have a substantially lesser neuropathy risk than the same dose over a year. Everything I've read suggests that all neuropathy symptoms are reversible upon cessation of the B6, in any case. If you get symptoms, you stop, and the symptoms go away.
> the official upper limit is "100mg"?
Yes, that is correct. It is safety factors within safety factors within safety factors. For a full account, read this chapter on B6:
http://books.nap.edu/openbook.php?record_id=6015&page=150
Toxicity/adverse effects and the derivation of the UL proceed from page 182.> multiple different brands at the store sold jars with 250mg pills. the sheet at the store said the neuropathy level is 2000-6000mg... confusing.
Early medical reports were not so carefully crafted as those published today. As I recall, in an older article, subjects taking 2000-6000 mg/day B6 for periods of 2 to 40 months reported neuropathy symptoms. Those variables cover an incredibly broad range of experience, so it's hard to make conclusions. What I can tell you is that neuropathy at 1,000 mg/day is thought to be uncommon. That's right in about the dose you were considering. And, if your fingers or toes start tingling or go numb, just cut the dose.
Lar
poster:Larry Hoover
thread:736055
URL: http://www.dr-bob.org/babble/alter/20070201/msgs/736058.html