14 replies to this topic

[navyblue]

Currently my multivitamin gives me: 25mg of B-6

I get another 50mg from my Source Naturals Ultra-Mag

I also take get another 50mg from my B-Complex

Am I over-doing it?

[pamojja]

First of all, learn from advises but always use your own discernment. Everyone's physiology is different and you might be the first to experience an effect never described before. On the other hand, there are many 'in vitro' warnings out there, which most of the times have never been replicated in a living body.

LiveExtension's 'Disease Prevention and Treatments' gives B6 the least level of concern for adverse effects.

It further states: In very high doses (more than 300-500 mg a day), this vitamin may cause a reversible neuropathy with symptoms of tingling and numbness in the extremities. High doses (more than 500 mg a day) should be used only when a blood test documents the failure of folic acid, vitamin B12 and TMG to lower homosysteine levels. Never take high doses of vitamin B6 without also taking the other the other B complex vitamins.
LifeExtensions itself sells Vitamin B6 capsules with 250 mg promoting Cardiovascular health*.

Burgerstein's 'Micronutrients in the Prevention and Therapy of Disease' sets its very high doses above 1000 mg/day where reversible peripheral neuropathy occurs. Doses above 500 mg/day or much higher for short periods (up to weeks) aren't considered toxic for healthy persons. Very large doses during breast feeding could deteriorate lactation.

Personally I take 150mg/day for a year without any adverse effects.

Regards..


*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

[ajnast4r]

way too much, especially if as p hydrochloride.. theres no need for that much b6 in a healthy adult

[navyblue]

Originally I had thought that since vitamin B-6 was water soluble that whatever I did not use would just end up in the toilette. Apparently this isn't the case, which is why I was confused about it. I guess what I will have to do then is take a magnesium supplement that doesn't include any B6, or just wait till I finish this one. Funk had recommended the chelated glycinate in another thread so I'll give that a shot next. The reversible neuropathy is not worth it to me. I'd rather just pay 10 bucks and get a different bottle of magnesium. 75mg/day sounds good to me.

[nameless]

What is considered the optimal amount of B6? Or for that matter, optimal amounts of all B vitamins?

[Sillewater]

I remember it being mentioned that 10mg would be the max for Pyridoxine HCL, however P5P and Pyridoxamine can be dosed in the 100mg's.

Any more than 10mg will flood the liver and the rest can't be converted to P5P and will bind the receptors thus blocking it.

[kismet]

Originally I had thought that since vitamin B-6 was water soluble that whatever I did not use would just end up in the toilette.

Water solubility plays no role. Pyridoxine is an inferior form and shouldn't be taken at all as far as I know. At this dose you're still at the risk of neuropathy. I'd take P5P/Pyridoxamine.

[ajnast4r]

What is considered the optimal amount of B6? Or for that matter, optimal amounts of all B vitamins?

200-300% DRI for healthy adults... higher amounts can be used for condition specific reasons, ie 100+mg of p5p in diabetics to prevent glycation damage.

Originally I had thought that since vitamin B-6 was water soluble that whatever I did not use would just end up in the toilette.

they are, and once your body has maxed out its ability to pull any more into the blood it will pass the rest. BUT that doesnt mean the super high amounts your body is capable of absorbing are the best or even healthy period. your body is a machine, there's no conscious though process to decide how much to take in... its hardwired to pull as much as i possibly can now because i may starve tomorrow.

btw b vitamins are active in the body for days, sometimes weeks after ingestion.. the whole 'oh youll just pee out what you dont need' is a bit a farse pushed by supplement companies to get you to buy b-complexes

[nameless]

What is considered the optimal amount of B6? Or for that matter, optimal amounts of all B vitamins?

200-300% DRI for healthy adults... higher amounts can be used for condition specific reasons, ie 100+mg of p5p in diabetics to prevent glycation damage.

Thanks for the reply. Would you consider 200%-300% RDA a recommendation across the board for all Bs (except folic acid) too?

And is this a recommendation based on Pyridoxine or P-5-P? One thing I am unsure about is I don't know if the more bioavailable Bs (P-5-P, Riboflavin-5-phosphate, 5-Methyltetrahydrofolate) are equivalent RDA-wise to the lesser forms, and if a person should take more or less of those. For glycation purposes, perhaps larger amounts would be suggested, but assuming a person doesn't have diabetes, sticking to 2-3x RDA for all Bs, regardless of forms, the recommended way to go?

The AOR multis seem to go a bit higher, as I see they contain 100mg P-5-P at full dosing. I'm taking a small dose of mix daily right now (1/4), so would be at approx. 25mg P-5-P, but really have no idea how much P-5-P is ideal or if that is too much.

[Blue]

LPI:
"Although vitamin B₆ is a water-soluble vitamin and is excreted in the urine, long-term supplementation with very high doses of pyridoxine may result in painful neurological symptoms known as sensory neuropathy. Symptoms include pain and numbness of the extremities and in severe cases, difficulty walking. Sensory neuropathy typically develops at doses of pyridoxine in excess of 1,000 mg per day. However, there have been a few case reports of individuals who developed sensory neuropathies at doses of less than 500 mg daily over a period of months. Yet, none of the studies in which an objective neurological examination was performed reported evidence of sensory nerve damage at intakes below 200 mg pyridoxine daily (24). To prevent sensory neuropathy in virtually all individuals, the Food and Nutrition Board of the Institute of Medicine set the tolerable upper intake level (UL) for pyridoxine at 100 mg/day for adults (see table below) (7). Because placebo-controlled studies have generally failed to show therapeutic benefits of high doses of pyridoxine, there is little reason to exceed the UL of 100 mg/day."
http://lpi.oregonsta...mins/vitaminB6/

NIM: "Vitamin B₆ (B₆) comprises a group of six related compounds: pyridoxal (PL), pyridoxine (PN), pyridoxamine (PM), and their respective 5'-phosphates (PLP, PNP, and PMP). The major forms in animal tissues are PLP and PMP; plant-derived foods contain primarily PN and PNP... ...Absorption in the gut involves phosphatase-mediated hydrolysis followed by transport of the nonphosphorylated form into the mucosal cell... ...Most of the absorbed nonphosphorylated B₆ goes to the liver. PN, PL, and PM are converted to PNP, PLP, and PMP by PL kinase. PNP, which is normally found only at very low concentrations, and PMP are oxidized to PLP by PNP oxidase... ...The absorption of B₆ compounds in the absence of food is comparable, even at very high doses. About 70 percent of a loading dose of 50 mg pyridoxal (PL) or the equivalent dose of pyridoxal phosphate (PLP) can be accounted for in the urine within 24 hours, demonstrating that the phosphorylated form is effectively hydrolyzed and absorbed in the gut (Shane, 1978; Snell, 1958). Under the same conditions, about 40 percent of an equivalent dose of PN can be accounted for in the urine, but PN at high doses raises the plasma PLP concentration and is retained more effectively than is PL (Shane, 1978). Similarly, dietary pyridoxamine (PM) and PL are about 10 percent less effective than PN in raising the plasma PLP concentration, and slightly more of these vitamins is excreted in the urine as 4-pyridoxic acid (4-PA) (Wozenski et al., 1980). Most controlled B₆ studies have used PN as the added B₆ source, but requirements calculated from these studies would underestimate the B₆ requirement by only 5 percent or less for individuals deriving most of their B₆ as PLP and PMP from animal sources."
http://books.nap.edu...i...15&page=150

Pyridoxine looks to be slightly better than pyridoxamine or P5P=PLP at raising plasma PLP levels. All the forms are converted to PLP. Any better effect by high-dose oral PLP or pyridoamine as compared to oral pyridoxine should be by themselves as they briefly exist in the body after absorption before they are converted to PLP. Since they are all converted to PLP about equally well I would not count on any of them being less toxic.

[ajnast4r]

Thanks for the reply. Would you consider 200%-300% RDA a recommendation across the board for all Bs (except folic acid) too?

yea, all b's other than folic acid which you should stick to the DRI 200ug synthetic and 400ug food folate.

i know ortho core has that huge dose of p5p but i personally would never consume that much... who knows about the long term saftey

[nameless]

Weird thing is, I assumed AOR Mix didn't have super high levels of Bs. Guess it's because I'm used to taking Multi Basics at a partial dose (although even that may go above the 2-3x range for some Bs) and thought Mix was in the same range. I feel sort of dumb not checking the label closer.

What reasoning does AOR have for going so high on B6, B12, etc? Reducing glycation?

I know other companies typically just include tons of Bs for marketing reasons. But I assume AOR has some scientific reason behind their choice (not saying it's a good choice, but there should be some logic there).

Edited by nameless, 19 October 2009 - 05:21 PM.

[ajnast4r]

What reasoning does AOR have for going so high on B6, B12, etc? Reducing glycation?

for b6 yes, glycation

[pamojja]

way too much, especially if as p hydrochloride.. theres no need for that much b6 in a healthy adult

I agree.

However, I came down with a heavy Claudatio intermittens a year ago and starting then very caudiously with very low doses and no improvement. But increasing all supplements within the short time of a few months my walking distance doubled from below 1 km - and what's more amazing to me - I even can walk fast again. :-)

While in good health no need for that hight doses, for sure.

Any more than 10mg will flood the liver and the rest can't be converted to P5P and will bind the receptors thus blocking it.

Tried to search the forum but till now couldn't find anything specific.

Could you explain a bid further how this happens, or links where I can read up?

Thanks.

[Sillewater]

Now that I think about it it may be more than 50mg, not 10mg. Its somewhere on the forum and I can't find it either.