Cases of toxicity have been reported at doses as low as 21 mg per day, the recommended daily intake is 1.3 to 2 mg. The person in question was diagnosed with issues possibly caused by this after 2 years.
Edit: Clarification, the 21 mg figure isn’t from this article but from a related document released by Australian Therapeutic Goods Administration.
https://consultations.tga.gov.au/medicines-regulation-divisi...
Another news source: https://www.theguardian.com/australia-news/2025/jan/05/simon...
Edit: read it again and that's based on 2 tablets per day (I take one) so I guess I get 20mg. Might cut it to every other day though.
That's very hard to believe. In my "normal" vitamin B-Complex supplement there is 20mg of B6 in the daily dose. If 21mg per day would cause nerve damage, that we'd know (and it would be an epidemic).
Since B6 is water soluble doesn't it mean most of it might just leave our body if not needed? (No storage in fat)
Vitamin B6 is an antioxidant and coenzyme involved in amino acid, carbohydrate and lipid metabolism. Humans cannot directly produce active vitamin B6 (pyrixodal phosphate). However, salvage pathways allow the enzymatic conversion of vitamin B6 vitamers, including pyridoxine, pyridoxal and pyridoxamine by the enzyme pyridoxal kinase, into active vitamin B6.
In the body, active vitamin B6 is involved in metabolic reactions including GABA synthesis, monoamine neurotransmitter metabolism, the metabolism of polyunsaturated fatty acids and phospholipids, amino acid metabolism and the conversion of tryptophan to niacin.
Vitamin B6 reduces homocysteine levels by acting as a coenzyme for both cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE) in the transsulfuration pathway following a postprandial methionine-load (after a meal). In the fasting state, homocysteine is primarily metabolised via the remethylation pathway which does not require vitamin B6.
In the transsulfuration pathway, homocysteine is converted to cystathionine by CBS, then to cysteine by CSE. During moderate vitamin B6 deficiency, CSE exhibits much greater loss of activity compared to CBS. However cysteine production is preserved due to an accumulation of cellular and plasma cystathionine in a larger substrate pool which compensates for reduced CSE activity. As CBS is a vitamin B6-dependent enzyme, CBS deficiency (typically genetic causes) can result in elevated fasting and post-methionine load homocysteine due to impaired synthesis of cystathionine from homocysteine. Elevated homocysteine levels increase oxidative stress, may inhibit nitric oxide synthesis, increase vascular endothelial cell damage and accelerate low-density lipoprotein (LDL) deposition in arteries.
Vitamin B6 may significantly decrease the rate of formation of kidney stones in patients with type I primary hyperoxaluria, a condition caused by a deficiency of the liver-specific enzyme alanine-glyoxylate:aminotransferase by reducing levels of urinary oxalate. The protective effect of vitamin B6 supplementation for kidney stones appears to only occur in women (-34% risk) and not men.
So even though it is water soluble it can still accumulate when taken at these high doses. Most supplements contain pyridoxine, which can acumulate and damage peripheral nerves. Indeed the form of B6 is important, and manufacturers take advantage of the fact that consumers (and medical practitioners) are unaware of the difference. Taking P-5-P may be less risky than pyridoxine hydrochloride, a cheaper option that is included in most supplements.
I'm curious, do you exercise every day? b6 seems to get flushed out of the body in proportion to how much exercise you get, as it gets released by the muscles and then only partially reabsorbed with each cycle. It's possible what you're taking would cause you nerve damage if you were sedentary.
The actual situation is probably that most people can take 2 or 3 times 20 mg per day (and some people can take 10 times 20) without problems. There is a lot of variance in the gut absorption and the rate of metabolism of a lot of micronutrients in the human body.
So, be careful about assuming one economies variant of a pill is the same as another. Same container, same branding.
"Ultra Muscleze® P5P," a product by BioCeuticals, contains 53.7 mg of the active form of vitamin B6 (pyridoxal 5-phosphate monohydrate) per tablet. This equates to 34.2 mg of pyridoxine (vitamin B6).
Interesting that they ostensibly make a version with the P-5-P form. I've read that the P-5-P form is less associated with neuropathy. As a personal anecdote, 50mg of pyridoxine hydrochloride daily for a couple of weeks gave me nothing except numb fingers (which resolved after a few weeks). However, 12mg of P-5-P with my magnesium supplement has been life-changing so far. Been taking 350mg of magnesium daily for a year or more but only when adding the P-5-P with it, do I have relief from cramps.
Anyone in the know: is there some condition that would explain this?
I started a software job in 1995, writing a lot of code. By mid-1997, I had severe nerve pain in both wrists, even with ice, stretching, and ibuprofen.
I went to an excellent orthopedist who prescribed two things: a Kinesis Advantage keyboard to mostly immobilize the wrists while typing, and 50 mg of Vitamin B6 per day.
The combination saved my career. I sometimes get out of the habit of taking the B6 for a week or two, out of sheer forgetfulness. After a couple of weeks, I'll start noticing very minor nerve pain if I'm using the Kinesis Advantage keyboard (I'm typing this on one right now.) But if I'm typing on a normal keyboard at a client site, a week or so is enough to bring back noticeable nerve pain, which reminds me to start the B6 regimen again. After a few days on B6, the pain recedes.
I was a little nervous at taking 2500% of the RDA, so I researched the medical literature, and the studies I found showing problems caused by excessive B6 all described people taking 200mg or more per day.
The article notes that "since 2022 the TGA has required a warning label for listed medicines with more than 10mg of B6." So maybe studies showing the potential for harm have come out since then; I don't know. On the other hand, has anyone ever gathered data to show whether supplemental B6 actually does improve cases like mine? Vitamin B6 can't be patented, so there's no money to be made, so who is going to fund that study?
In pregnant adult women, vitamin B6 is likely safe at a dose of up to 100 mg per day. In adolescent pregnancy, vitamin B6 is likely safe at a dose of up to 80 mg per day.
In lactating adult women, vitamin B6 is likely safe at a dose of up to 100 mg per day. In adolescents who are lactating, vitamin B6 is likely safe at a dose of up to 80 mg per day.
In children, vitamin B6 is likely safe at a daily dose of 30 mg (1-3 yrs), 40 mg (4-8 yrs), 60 mg (9-13 yrs) and 80 mg (14-18 yrs).
The likelihood of side effects increases at doses higher than 200 mg per day.
In 2023, the European Food Safety Authority set an upper limit of vitamin B6 of 12 mg per day for adults, and 2.2 to 10.7 mg per day for infants and children.
Source: https://inspectsupplement.com/vitamin-b6 (Edited Note: My Website)
Here's a good one https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfession...
After one night and day of sweating profusely and feeling really bad, and me thinking I've cached a bug on my daily public commute, I didn't think about it any more, until days later when I began shedding the top layer of skin on my palms. Like, big flakes just started to fall off. Similar to what happens when you've had a severe sun burn.
Once that was over, any my palms were back to normal, it was then I noticed that compared to previously, my sense of touch wasn't what it used to be. Also, I noticed that I wasn't sweating as much any more. It was at this point I went to see my GP who confirmed elevated levels of B6 but didn't give any other diagnosis. This was two weeks later though and I was still sporadically consuming energy drinks, but it made me remember reading about B6 toxicity, so I began looking into it.
My own suspicion is that overconsumption of B6 damaged the nerve endings under my skin leading to a reduction in touch and the ability to sweat.
So now I live my life with about a 25 to 50% reduction (subjective) of my sense of touch. Plus I barely sweat any more (which has it's upsides). Before, I was an "easy sweater" and would begin to sweat if I walked a kilometer to the train station in the summer (20C or so), but now I can be out all day in 30+ weather (~90F) without as much as a drop of sweat.
I still sweat if I do actual prolonged physical exercise, like when I'm at the gym or exercise bike, but during daily life, not really any more. Also my hands are always dry and as a side effect quite slippery.
So yeah, stay clear of vitamin supplements and overconsumption of energy drink. I'm just happy it wasn't worse in the end, as I've read about many life changing cases of B6 toxicity.
And this is hard do to if you weren't intentionally controlling or at least logging your water intake among other factors.
Do you realise that sweating is the body's way of thermoregulating? Your body has partially lost the ability to thermoregulate as much as it used to.
Your conclusion of staying away from vit supplements (as opposed to energy drinks who are not health at all) is a very curious one. If you are anything like the average citizen, you are likely vitamin deficient in some form or another. Staying away from supplements while keeping energy drinks is not a great choice health wise.
I would assume that everyone on this site understands that. The fact that they explicitly noted that there were upsides shows that the downsides are quite obvious.
Had an experience with a missed type 1 diabetes diagnosis causing neuropathy in a loved one. There is a surprising amount of actionable scientific literature out on neuropathy and all sorts of other issues commonly discussed as best-you-can-do-is-wait-and-see. Once you happen to dig in and start reading.
I remember reading papers on acetyl-L-carnitine helping with diabetic neuropathy, and it was our clear experience that it did help.
There were other supplements which helped with various similar repercussions of a severe and prolonged state of elevated blood sugar, which causes oxidation and tissue damage, and isn’t dissimilar to B6 toxicity as it seems. I don’t remember exactly which nutrients/OTC medications seemed to help neuropathy, but I’d suggest looking into alpha lipoic acid (ALA; more specifically Na-R-ALA), argine, maybe BCAAs in the context of mitochondrial function. Probably some other stuff that has results out on it too.
I’d also suggest reading the molecular biology and neuroimmunobiology on NMDA receptor antagonists and 5-HT2A receptor agonists, classes both of which are shown to be “profoundly immunomodulating” as one paper put it – reducing inflammation, including neuroinflammation – as well as encouraging neuroplasticity, which is also useful in peripheral nerves. The discussion of these known molecular-biological results and implication is unfortunately swamped by various social effects; the best-known NMDA receptor antagonist is called “Ketamine”, haha, and 5-HT2A agonists are usually known as psychedelics and, uh, yeah… molly. The partying and the “wheeee” factor isn’t interesting to me; the neuroimmunobiology of it is!! And I, yeah, I emphatically recommend reading the scientific literature on that.
And generally looking for recent papers on nutrients/supplements/OTC medications in the context of all kinds of similar issues. There are often results in one sub-specialization which are applicable to other things. You don’t need to limit yourself to randomized controlled trials, especially if considering supplementation of compounds known to be safe, rather than medication; Molecular biology is molecular biology, and it’s implausible to me that the placebo effect will reliably improve things like chronic neuropathy. Or insulin sensitivity. I’ve seen direct results on continuous glucose meters and all manner of labwork that confirm this view. —Don’t believe me; I deeply and emphatically recommend reading academic literature.
To paraphrase a nice-seeming guy,
Read papers. Mostly published. Not too slowly.
ps., Claude is unusually good at navigating the scientific landscape!
I drink a zero-calorie energy drink every morning for the past 10 years and I've never had any issues.
I also had problems with irritability. Especially if I got hurt in some way (like sprained wrist). If I get this way now, it is a clear sign I need to take B6. It fixes it right up.
Both elements are something the body requires in the diet and does not store much. If you go to doctors most will tell you magnesium and b6 have nothing to do with sleep and give you melatonin, which is utterly useless to take regularly. It is very unfortunate how the medical profession is useless regarding fixing well being issues.
Insomnia can of course manifest itself through many causes, but taking energy drinks would definitely help very few. B12 is something the body stores so your lifestyle and diet must be quite shit to have a deficiency.
Magnesium and B6 on the other hand you can become deficient very quickly.
In fact, ATP exists typically as MG-ATP in the body.
Severe Deficiency is rare (or rarely diagnosed i should say) because the body maintains serum magnesium levels at the expense of skeletal mg.
I was borderline low on D and B12, but everything else was normal. So I take B12 and only take D in the winter. I would never take a general vitamin.
There's some people on the internet that advocate taking massive doses of D. But the side effects (short term and long term) are just as nasty as having a deficiency.
Anyway, get your blood tested and only take what's necessary.
You can take quite an amount of Vitamin D safely, an example: "Results of daily oral dosing with up to 60,000iu of vitamin D3 for 2 to 6 years in 3 adult males"
Without a multi-vitamin I'd likely get some sort of vitamin/nutrient deficiency, I imagine.
Holy hell...how is that even sold like that. That's going in the bin I guess
Luckily I haven't been taking it regularly. Been leaning more & more towards taking a multi-vit every 2-3 days instead of daily.
In all though I had pretty much every symptom listed here: https://understandingb6toxicity.com/b6-toxicity/symptoms/
It's actually pretty crazy, I tested recently because I was curious and for the first time since I completely stopped B6 I took a 10mg dose and that evening my muscle spasms came back, my nervous system is so whacked out from this. This experience is what turned me off from supplements, it's horrible.
viraptor•1d ago
Btw, if you take more than 100mg, the serum level will easily go out of range for usual labs. (400+ nmol)