Danger of mega dosing vitamins

[jobe28]

Hi. Ive been diagnosed with schizophrenia since about 3 years ago. I recently came across a book saying I might be able to treat it with mega-doses of vitamin b3 -- anywhere from 3 to 30 grams a day.

The LD50 for vitamin b3 (niacinamide) is 2500 mg/kg.. so 212 grams for me. This is obviously a lot higher than the dosage i would be looking at but my question is this..

if I were to take about 30 grams every day, would there be any sort of "cumulative" effect -- making the amount of it in my system higher? I have no idea how it would effect me over a long period of time (i plan to continue this for at least 2 years), but Im certain that its safe (it was recommended in a book - "orthomolecular treatment of schizophrenia" if youre interested). Im just double checking.

 

[Black Rabbit of Inle]

tds --> hl

 

[King-Anubis]

The LD50 you've given is more then likely for acute doses, what you're talking about is chronic dosages - and very high ones over a very long time.

Anyway, with chronic dosing of 30g a day I would be very surprised if you didn't suffer from some form of liver failure within a few months at the most. Yeah you're liver - if it's a champ - could get away with that sort of dosing for a few days, but long term it would be highly hepatotoxic (Would be like chronic paracetamol usage I would imagine). If you do drink or take other drugs it'll only exacerbate the problem since your liver will have even more work to do.

I wouldn't even recommend taking it at 3g chronically, I don't see it worth the risk of liver failure. Most of these experimental treatments are poorly researched and potentially deadly (EDIT: I had another look, although there are a few studies they're not really conclusive). As a schizophrenic myself I have heard this one before, but I don't see it doing any good long term. Short term, perhaps? Serotonin seems to be involved somewhere in the metabolisim of B3 so that's probably it's mode of action in treating schizophrenia (I would assume moving serotonin away from the brain, or something similar.)

On top of hepatotoxicicity, B3 also raises your blood sugar levels. Since I'll assume you take some form of antipsychotic medication which already increases the likelyhood of developing diabetes, taking megadoses of B3 chronically will only further increase this risk - buy a WIDE margin (I think I read that 3g raises blood sugar by up to 10%, so god knows what 30g will do.) This will also put pressure on your Pancreas potentially causes some problems there too.

TL;DR: Probably not a good idea long term, but possibly short term (maybe at LOW doses, over a few days). Don't think it's worth the risk of death.

 

[jobe28]

Do you think the psychiatrist who wrote the book would lie about people taking these sort of doses?

 

[Foreigner]

AFAIK there are no documented cases of niacin overdose and death. It's a water soluble vitamin so any excess will be excreted, however the sheer large amounts you're taking still pose a burden on the liver and kidney systems to push it out of your system. I think if there are any toxic effects they will be noted in those two systems over time. Vitamins in pure form are still technically xenobiotics that the liver must process -- your body will not treat them as a nutrient at such high levels.

I think most of the side effects you'd experience are not fatal, but there could still be side effects. Large doses of niacin can cause flushing, itchy skin, increased heart rate, stomach pains and vomiting, dizziness, etc. I would say if you have a heart problem or low blood pressure, you should not do it because it might make you tachycardic.

I've read many of the abstracts on vitamin therapy and IMO it is mostly unverified. Naturopaths swear by vitamin therapy but unless you are actually deficient in said vitamin I don't think it will do anything. And honestly I don't see the connection between B3 and schizophrenia. It's rare to be deficient in niacin if you live in the developed world.

 

[flyhighk]

If you still wanna try megadosing the stuff, I suggest doing blood work. I mean, better safe than sorry.

 

[red22]

King-Anubis you need to provide sources for the claims you're making.


This is what an advocate of the therapy says about the alleged liver damage.

The LD50 for vitamin b3 (niacinamide) is 2500 mg/kg..

Vitamin B3 refers to both niacinamide and niacin.


Liver Problems—Rarely, vitamin B3 will cause jaundice. In working with niacin for the past fifty years, I (A. H.) can recall fewer than five patients who developed jaundice. All recovered and one went back onto niacin with no recurrences. Many of the patients were alcoholics, who are more prone to jaundice. None died and some, it was discovered, were jaundiced from tranquilizers—when they were discontinued and the niacin retained, the jaundice cleared.

Many years ago, after the cholesterol-lowering effect of niacin was confirmed, some physicians became concerned because liver function tests showed dysfunction even though no jaundice was present. They took liver biopsies on a number of patients who had used 3,000 mg of niacin per day for one year. Histological examination with electron microscope revealed no evidence of liver dysfunction. Since then, many have noted that if the test is done while patients are taking niacin, the SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) will be elevated. It is my policy to ignore these findings unless there is clinical evidence of liver dysfunction. No liver function test is valid unless the patient has been off niacin for 5-7 days; if there is no jaundice, the tests will then be normal. Apparently, liver function tests remain normal if the dose of niacin is built up slowly.

It is likely that niacin interferes with the mechanics of the liver function test or else niacin has some effect in the liver that tends to exaggerate these effects. Thus, niacin increases bilirubin levels because it competes with bilirubin at the hepatic uptake level. It induces hyperbilirubinemia in patients with Gilberts syndrome. It might be a good idea to do routine bilirubin values before starting niacin to determine whether Gilberts syndrome patients are more apt to show abnormal liver function tests on niacin.


Orthomolecular Medicine for Everyone by Abram Hoffer, Andrew W. Saul
http://books.google.com/books?id=mUIrfIcsX1IC&pg=PA81