No need to worry about too much B12. The better lab ranges don't even have a number for 'high.'

Most neuros know little or nothing about B12, and that is terrible shame, since the results of too little is a matter for their specialty.

rose

--itis true that overdosing on B6 can have deleterious effects, particularly neuropathy--

http://www.neuro.wustl.edu/neuromusc...yridoxineintox

--but this is only on major doses that are well above those available in most B-complex formulations on the market. Of course, people can abuse vitamins as they can any other substance, and some who may be taking multiple b-complexes with very high B6 values may be putting themsleves at risk.

Interestingly, these effects have only been reported with the pyridoxine form of B6. Certain companies now sell the enzymatically activated P-5-P form of B6, which seems to be more easily metabolized and safer, as it does not need to be converted from pyridoxine in the liver, and it may also bypass certain genetic enzymatic deficiencies (though these would typically result in not enough B6 absorption rather than too much).

Well, all of us can be unclear. Even Glenn.

The B6 doses that cause problems after long use are generally several times above that found in a B complex.

rose

I'm glad to hear that. It had me a bit worried as I'd seen it in several different places but they weren't clear about how much was too much.

--I was trying to post very quickly, and apparently didn't edit well enough (I went back in and made some corrections just now).

I really ought not to post on days when the SAT is given.

I don't see any details posted here as to the content of the B-complex being asked about. Without that, really there is no answer.

Most people tolerate B-complex well. Many seek it out in high dose because
it usually makes people feel better. In fact I can get too strung out on high dose and get hyper if I don't watch myself (this is B-100 once a day).

There are B formulas that are rather mild with 5-10mg of B's in them.
Then there are B50's, B100's and even B150's. So without knowing the content being asked about, this question is rather hard to respond to.

The B-6 controversy involved grams of B-6 taken for months/years. It was a handful of patients who developed a neuropathy from so much.
B6 was at one time given in huge doses for PMS. And B-6 is the only vitamin that demonstrates toxicity in very high doses, and when extremely low. Same symptoms.
http://ods.od.nih.gov/factsheets/vitaminb6.asp
Here is the newest suggestion from that site:
Here is a recent paper:
As I said...there are typically handfuls of patients affected by high B-6... not as common as many side effects of DRUGS for example. But enough to warrant caution as far as extremely high dose goes.

Wow. What a way to say a whole bunch of contradictory things about B-6! From what I read it pretty much sounds as if B-6 should mostly be ignored. They can't seem to prove that it helps in a any way even if they show a person is deficient in B-6. In other words, if you're suffering from a lack of B-6 adding a supplement doesn't appear to help. So then what?

Its usefulness is stated even in medical textbooks, and they are using the pyridoxine type. Too much can be a problem, but too little is damaging.

P-5-P is a better bet, as MrsD has shown us for a very long time.

B6 (especially pyridoxine) is certainly not a vitamin to take in super mega-doses without good reason, but it is important to make sure one is getting enough in a form that can be used.

rose