My method for prevention and control of my POIS symptoms - 80% to 100% effective

[Rock76]

Quercetin seems really interesting, but I am reading this
https://www.mountsinai.org/health-library/supplement/quercetin

"Preliminary evidence suggests that a byproduct of quercetin can lead to a loss of protein function. Very high doses of quercetin may damage the kidneys. You should take periodic breaks from taking quercetin. At doses greater than 1 g per day, there have been reports of damage to the kidneys."

If more than 1g can be bad, I don't feel completely safe at half a gram, especially long term.
Also I have read elsewhere that it has a diuretic effect and that it can cause tingling/neuropathy.

Any concern in your opinion?

In my own experience, I never used it daily.  I use it in my pre-pack, and whenever I have allergy symptoms, combined with Vitamin C ( it is very effective for runny nose and sneezing).  The formula I used never caused me any harm ( 500mg Q with bromelain added).
So, maybe better not taking the phystosome formula, after all, because it would equal to a large intake.  My regular, 500mg capsules, are ok for me.   

My approach, as illustrated by my pre-pack method, is too take a ibt of many substances rather than a lot of a single or a few substances.  This approach is based on the fact that many side effects are dose-dependent, meaning that they get worse as the dose increase.  By using low to normal doses with anything, I play safe.

Yes I was thinking the same, the phytosome one could be really dangerous.

Still regarding 'normal' quercetin (not phytosome) There's no long term data, If it can be harmful short-term at 1g+, maybe it's dangerous too at 250-500mg long term, We just don't know, I am not feeling completely comfortable with the 'normal' 500mg one even if just once-twice a week.
I will probably try it anyway soon.

[Rock76]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

[Quantum]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

To my knowledge, there is no interaction between vitamin b6 and b12, and quercetin.

CYP3A4 is not an issue with B vitamins, but there will be an interaction with the drugs eliminated by this liver enzyme.  However, quercetin is only a weak inhibitor fo CYP3A4 ( see https://en.wikipedia.org/wiki/CYP3A4#Ligands for details)

[Rock76]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

To my knowledge, there is no interaction between vitamin b6 and b12, and quercetin.

CYP3A4 is not an issue with B vitamins, but there will be an interaction with the drugs eliminated by this liver enzyme.  However, quercetin is only a weak inhibitor fo CYP3A4 ( see https://en.wikipedia.org/wiki/CYP3A4#Ligands for details)

Thank you. I asked because last year I developed a neuropathy (electric zap in 1 foot and a feeling of light internal trembling all over the body) after consuming an excessive amount of vitamin B6.
I was extremely worried when those symptoms started. I consumed 50mg a day which seemed very safe according to the US FDA daily upper limit of 100 mg, but later I found out that in Europe the upper limit is only 25mg and in UK even lower at just 10mg, so there seem to be major concerns about this Vitamin B6 which incredibly the US FDA doesn't know/understand.

Luckily my neuropathy resolved after some months but I have been in contact with people with B6 toxicity who had it for years and can't get out, like a neurological permanent damage.   

So I'd like to try quercetin for my POIS but after reading it might create tingling/neuropathy I am a bit worried. I have also found out quercetin significantly inhibits iron absorption, which by itself can create anemia and neuropathy, yes I guess this can be fixed by iron supplements but overall I am bit worried.

[BoneBroth]

Last months I also have got "electric zap" in my left foot under the heel and forward and also a tingling feeling in the skin of in my left leg. I've been taking B-complex with 25 mg, sometoimes I take it three times a day (75 mg). But the symptoms doesnt come when I've been out of POIS for a longer time (and still take the B-complex). I'm not so sure it's the vitamin B6 thats the bad guy here. Maye its the sublingual B12/folate (which skyrocked at at blood analyse). Or maybe POIS'ers are more prone to B6-excess then others. Or maybe a leaky gut absorb more of some vitamins. Well, my experience and gut feeling sais that there is much more likely to experience symptoms from deficiencies then excess.

[berlin1984]

P5P is supposed to be safer than normal B6.
i have a B-complex with "active" forms containing (for example) P5P instead of B6.

[Rock76]

P5P is supposed to be safer than normal B6.
i have a B-complex with "active" forms containing (for example) P5P instead of B6.

Supposed to be safer but it's not, P5P is what I got toxic from, and many people I am in contact with on some B6 groups got toxic from P5P, basically both forms are toxic

it seems many US researchs on B6/P5P are faulty and the FDA still has an upper limit of 100mg
which is largely different from Europe (25mg) and UK (10mg)

[Rock76]

Last months I also have got "electric zap" in my left foot under the heel and forward and also a tingling feeling in the skin of in my left leg. I've been taking B-complex with 25 mg, sometoimes I take it three times a day (75 mg). But the symptoms doesnt come when I've been out of POIS for a longer time (and still take the B-complex). I'm not so sure it's the vitamin B6 thats the bad guy here. Maye its the sublingual B12/folate (which skyrocked at at blood analyse). Or maybe POIS'ers are more prone to B6-excess then others. Or maybe a leaky gut absorb more of some vitamins. Well, my experience and gut feeling sais that there is much more likely to experience symptoms from deficiencies then excess.

you better stop the B6 immediately, When I took it (it was P5P which in theory is much safer but it's not) I used 50mg daily, for 1 month I felt like 20 years younger, incredible really, then the problems started

maybe people with POIS are more prone, yes

[BoneBroth]

Pyridoxine hydrochloride is the form of B6 I take (in a mix of all B-vitamins). According to the naturopathic doctors:

Recommended daily dose: 1-2,5 mg.
Optimal daily dose: 10-100 mg.
Terapeutic daily dose: 100-500 mg.

[Progecitor]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

In regard of CYP3A4 this may also need to be considered :

Prostate cells also express CYP3A4 that can inactivate T by conversion to mainly 6BOH-T (with 2B-, 15a/B- and 11B-hydroxyl side product formation and a decrease of CYP3A4 expression is observed in prostate cancer.
https://www.sciencedirect.com/science/article/pii/S0303720717304525

[Rock76]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

In regard of CYP3A4 this may also need to be considered :

Prostate cells also express CYP3A4 that can inactivate T by conversion to mainly 6BOH-T (with 2B-, 15a/B- and 11B-hydroxyl side product formation and a decrease of CYP3A4 expression is observed in prostate cancer.
https://www.sciencedirect.com/science/article/pii/S0303720717304525

and what does that mean ?

[Rock76]

Pyridoxine hydrochloride is the form of B6 I take (in a mix of all B-vitamins). According to the naturopathic doctors:

Recommended daily dose: 1-2,5 mg.
Optimal daily dose: 10-100 mg.
Terapeutic daily dose: 100-500 mg.

I used to read US FDA limits only, but after what happened I don't trust US upper limits anymore, I prefer European, which are in many cases lower, stricter and obviously safer.  (I live in Italy)

[demografx]

…I don't trust US upper limits [dosing] anymore…

Me, neither. I followed my OTC meds’ upper (and unsafe!) limit dosing and recently landed in the hospital’s Emergency Room, unable to walk a straight line without falling.

[Progecitor]

Can you help me understand if Quercetin raises or lowers vitamin b6 and b12 ? and how much ?

I seem to remember a website where it was said they were lowered but I can't find it anymore.
I have found here
https://www.liebertpub.com/doi/full/10.1089/act.2018.29197.mho
that it inhibits CYP3A4, don't know if it matters

In regard of CYP3A4 this may also need to be considered :

Prostate cells also express CYP3A4 that can inactivate T by conversion to mainly 6BOH-T (with 2B-, 15a/B- and 11B-hydroxyl side product formation and a decrease of CYP3A4 expression is observed in prostate cancer.
https://www.sciencedirect.com/science/article/pii/S0303720717304525

and what does that mean ?

I don't actually know how important this is. It only means that quercetin by inhibiting CYP3A4 may somewhat reduce the inactivation of testosterone. CYP3A4 also has a complex role in vitamin D metabolism.

Second, there was a highly significant correlation of 24-hydroxylase activity of 1aOHD2 with CYP3A4-mediated testosterone 6B-hydroxylase activity in a panel of 12 characterized human liver microsomes. The liver microsomes with the highest testosterone 6B-hydroxylase activity had the highest 24-hydroxylase activity. Third, dose-response studies showed that 24-hydroxylase activity in hepatic microsomes and recombinant CYP3A4 was inhibited in parallel by ketoconazole, a-naphthoflavone, isoniazid, and troleandomycin, known inhibitors of CYP3A enzymes.
We reported previously that CYP3A4 25-hydroxylates vitamin D2 and not vitamin D3. That the patient responded to modest pharmacologic doses of vitamin D2 by increasing serum 25OHD and serum calcium and healing the bone disease is attributed to 25-hydroxylation of the vitamin by CYP3A4.
https://academic.oup.com/jcem/article/90/2/1210/2837019?login=true#53049631

Importantly, induction of CYP3A4 in the small intestine could cause local tissue vitamin D deficiency and possibly directly affect intestinal calcium absorption.
https://sci-hub.se/https://www.sciencedirect.com/science/article/abs/pii/S0960076012001689

These data suggest that 1,25D3-dependent, VDR-mediated induction of CYP3A4 may constitute a chemoprotective mechanism for detoxification of enteric xenobiotics and carcinogens.
https://www.sciencedirect.com/science/article/abs/pii/S0006291X02027420

I couldn't find any indication between CYP3A4 and vitamin Bs, however it may worth considering that both testosterone and vitamin D have a correlation with vitamin Bs.

Vitamin b6 deficient animals have either a reduced rate of synthesis of testosterone or an increased rate of metabolic clearance compared with vitamin b6 supplemented controls, and this appears to be associated with enhanced target organ response to the hormone.
https://www.sciencedirect.com/science/article/abs/pii/0022473184903480

Vitamin D deficiency changes the intestinal microbiome reducing B vitamin production in the gut. The resulting lack of pantothenic acid adversely affects the immune system, producing a "pro-inflammatory" state associated with atherosclerosis and autoimmunity.
https://www.sciencedirect.com/science/article/abs/pii/S0306987716303504