Can Vitamin B-6 be dangerous?

[Mesomorphyl]

Well can it? Here is some info even though vitamin companies still sale 250-300mg tablets...

Too much vitamin B6 can result in nerve damage to the arms and legs. This neuropathy is usually related to high intake of vitamin B6 from supplements, [2] and is reversible when supplementation is stopped. According to the Institute of Medicine, "Several reports show sensory neuropathy at doses lower than 500 mg per day" [1]. As previously mentioned, the Food and Nutrition Board of the Institute of Medicine has established an upper tolerable intake level (UL) for vitamin B6 of 100 mg per day for all adults [1]. "As intake increases above the UL, the risk of adverse effects increases [1]."

[1] Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. National Academy Press. Washington, DC, 1998.

[2] Selhub J, Jacques PF, Bostom AG, D'Agostino RB, Wilson PW, Belanger AJ, O'Leary DH, Wolf PA, Scaefer EJ, Rosenberg IH. Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis. N Engl J Med 1995; 332:286-291.

Read on to the next post for more info.

[Mesomorphyl]

Vitamin B6 and the nervous system
Vitamin B6 is needed for the synthesis of neurotransmitters such as serotonin and dopamine . These neurotransmitters are required for normal nerve cell communication. Researchers have been investigating the relationship between vitamin B6 status and a wide variety of neurologic conditions such as seizures, chronic pain, depression, headache, and Parkinson's disease [1].

Lower levels of serotonin have been found in individuals suffering from depression and migraine headaches. So far, however, vitamin B6 supplements have not proved effective for relieving these symptoms. One study found that a sugar pill was just as likely as vitamin B6 to relieve headaches and depression associated with low dose oral contraceptives [2].

Alcohol abuse can result in neuropathy, abnormal nerve sensations in the arms and legs [3]. A poor dietary intake contributes to this neuropathy and dietary supplements that include vitamin B6 may prevent or decrease its incidence [1].

Vitamin B6 and carpal tunnel syndrome
Vitamin B6 was first recommended for carpal tunnel syndrome almost 30 years ago [4]. Several popular books still recommend taking 100 to 200 milligrams (mg) of vitamin B6 daily to treat carpal tunnel syndrome, even though scientific studies do not indicate it is effective. Anyone taking large doses of vitamin B6 supplements for carpal tunnel syndrome needs to be aware that the Institute of Medicine recently established an upper tolerable limit of 100 mg per day for adults. There are documented cases in the literature of neuropathy caused by excessive vitamin B6 taken for treatment of carpal tunnel syndrome [5].

[1]Bernstein AL. Vitamin B6 in clinical neurology. Ann N Y Acad Sci 1990;585:250-60.

[2]Villegas-Salas E, Ponce de Leon R, Juarez-Perez MA, Grubb GS. Effect of vitamin B6 on the side effects of a low-dose combined oral contraceptive. Contraception 1997; 55:245-8.

[3]Vinik AI. Diabetic neuropathy: pathogenesis and therapy. Am J Med 1999; 107:17S-26S.

[4]Copeland DA and Stoukides CA. Pyridoxine in carpal tunnel syndrome. Ann Pharmacother 1994; 28:1042-4.

[5]Foca FJ. Motor and sensory neuropathy secondary to excessive pyridoxine ingestion. Arch Phys Med Rehabil 1985; 66:634-6.

Hope this helps you make an informed decission on its use.

[Roid Rage]

Thanks for the info bud... as always...

[Moosepellet]

It can cause permanent nerve damage if taken in excess

[Roid Rage]

Hmm i still find myself a bit lost after read that post by meso about the B6... it seems as if taking more than 100mg of B6 can be harmful however it doesn't say what a safe amount would be...

From the read i think somewhere aroudn 50mg of B6 a day would be ideal?

RR

[swoll4589]

shit ive been taking 200mg ED. Ill cut it back to 100.

[Roid Rage]

shit ive been taking 200mg ED. Ill cut it back to 100.

haha wow

[Dave321]

I think this is very interesting meso, and you definately got me thinking. The only question I have is, do vitamens, such as b6 have to meet any form of regulation... health regs, govnt?? I'm just curious because I have purchased in the past B6 tabs that were 500mg/tab. and suggested consumption was 500mg/day. Mind you, they were slow release, but still 500mg for the day. I'd like to hear your thoughts on this.

[dwaynewade]

duration of supplementation obviously is a factor...

[dr.shred]

b6 pathonic acid? I take 1000mg a day. It was reccommended by a nutritonist to take that amount.

[dr.shred]

my bad I meant b5 not b6.

[Giantz11]

Shred was this suggested to you as a means to improve skin....or because of B5's involvment in Acetyl CoA?

[sinista63]

here are the doses that have been shown to cause neuropathy in humans:

MAXIMUM DAILY DOSE DURATION REFERENCE
75 mg 2 yr Dalton, 1987
200 mg 36 mo Parry, 1985
500 mg 8 mo Parry, 1985
500 mg 24 mo Parry, 1985
500 mg 2 yr Berger, 1984
500 mg 8 yr Podell, 1985
2 grams 24 mo Parry, 1985
2 grams 36 mo Parry, 1985
2 grams > 12 mo Parry, 1985
2 grams > 12 mo Parry, 1985
2 grams 3 mo Parry, 1985
2 grams 4 mo Schaumburg, 1983
2 grams 40 mo Schaumburg, 1983
2 grams 34 mo Schaumburg, 1983
2 grams 2 yr Friedman, 1986
2.5 grams 12 mo Parry, 1985
2.5 grams 9 mo Parry, 1985
2.5 grams 6 yr Davidson, 1984
3 grams 4 mo Schaumburg, 1983
3 grams 6 mo Vasile, 1984
3.5 grams 10 mo Parry, 1985
3.5 grams 1 mo Parry, 1985
4 grams 72 mo Parry, 1985
4 grams 10 mo Schaumburg, 1983
4.5 grams 12 mo Parry, 1985
5 grams 2 mo Schaumburg, 1983
5 grams 2 mo Parry, 1985
5 grams 4 mo Parry, 1985
6 grams 3 mo Schaumburg, 1983
10 grams acute Harati, 1986
132 grams over 3 days Albin, 1987
183 grams over 3 days Albin, 1987


as far as i can recall, the only form of b6 that is regulated is the intramuscular formulation. otherwise the vitamin can be purchased over-the-counter. the reason for manufacturers producing doses of 250 mg, 300 mg, and 500 mg/pill is that there are genetic enzyme deficiencies that cause pyridoxine dependance for which doses of 250 mg - 600 mg have been used. if i was that patient i wouldn't want to have to take twenty-four 25 mg pills to get that dose. its not good that they would recommend 500 mg/day on the label without specifying that it should be taken under the supervision of a physician. i guess they're not afraid of lawsuits.

[sinista63]

1000 mg/day of b5 shouldn't be a problem. doses of up to 10 g have been used to treat acne. high doses may just cause some diarrhea.

[Mesomorphyl]

I think this is very interesting meso, and you definately got me thinking. The only question I have is, do vitamens, such as b6 have to meet any form of regulation... health regs, govnt?? I'm just curious because I have purchased in the past B6 tabs that were 500mg/tab. and suggested consumption was 500mg/day. Mind you, they were slow release, but still 500mg for the day. I'd like to hear your thoughts on this.

Vitamins are not regulated or we would have to get prescriptions. Someone stated there may be a reason based on inherent deficencies or through a breakdown process that would have to be genetic... I have taken 200mg ed for 10 weeks, but I would not do that anymore. 100mg per day maximum for me.