Posted by Larry Hoover on June 27, 2004, at 7:50:52
In reply to Re: Niacinamide: liver-safe amount?, posted by guttersnipe on June 26, 2004, at 0:10:54
> Hi folks, I hope my query doesn't take this thread too far off-topic ...
>
> Q: Does anyone know of any scientific evidence indicating what is a safe level of niacinamide -- i.e., one that does not present a risk of liver toxicity? I have searched many websites but most of what I've found on the subject is along the lines of "I've heard that X amount is safe" with no citations and with widely varying ideas as to how much X amount is.
>
> Much obliged for whatever info anyone can provide.The issue of the safe use of a supplement is never off-topic, IMHO.
The hepatotoxic effects of high-dose niacin therapy (e.g. for high blood lipids) first emerged with sustained-release niacin. The sustained-release form was sometimes associated with liver problems at doses as low as 3 grams per day. Even those cases seemed to be presented in the literature as case reports, suggesting it was a somewhat uncommon phenomenon, but certainly worth watching for in all treated patients.
Now, one theory of the increased toxicity of the sustained release formulation is that a greater proportion of it gets shunted down the niacinamide pathway, compared to the conjugation pathway (which causes that yucky flushing feeling). That would seem to implicate niacinamide itself for the toxic reaction, yet I cannot find so much as a case report of a single instance of liver problems related to niacinamed intake.
One hypothesis holds that the liver stress is mediated by depletion of the universal methyl donor, S-adenosyl methionine (SAMe). If that is indeed the case, then ensuring intake of SAMe promoting supplements such as betaine (also known as trimethylglycine (TMG)), and B-12 with B-6, would be altogether preventative of toxic effects.
IMHO, anyone attempting to treat anxiety-related stress with niacinamide should commit to taking a B-complex with added B-12, in any case. Any time you supplement with a lone B-vitamin, you risk placing further stress on systems dependent on other B-vitamins. This may simply be an explicit example of such a consequence.
Lar
poster:Larry Hoover
thread:355634
URL: http://www.dr-bob.org/babble/alter/20040613/msgs/360898.html