Vitamin B6 toxicity or overdose

[natlp]

Would appreciate it if anyone has in-depth info on B6 toxicity. Have found some info on Internet about it causing nerve damage. Doctors dont seem to know much. They think I might have Parkinson’s, but I think it might be the B6 supplements I took for years. My tested blood level of B6 was way above normal. Thank you so much!

[Qadgop_the_Mercotan]

3.3.9.D Neuropathy

1. Summary

a) Peripheral sensory neuropathy or neuropathic syndromes have been associated with prolonged use of oral pyridoxine. Although these syndromes were initially observed following administration of high doses (2 to 6 grams daily) (Schaumburg et al, 1983; AMA Department of Drugs, 1986b), more recent reports have described peripheral neuropathy with lower doses (50 to 500 mg daily) (Parry & Bredesen, 1985; AMA Department of Drugs, 1986b; Dalton & Dalton, 1987; Bender, 1989a). Neuropathic symptoms generally subside after withdrawal of pyridoxine (Waterston & Gilligan, 1987; McLachlan & Brown, 1995; Ludolph et al, 1993; Berger et al, 1992; Nisar et al, 1990; Bender, 1989a).

2. LITERATURE REPORTS

a) Uncontrolled studies allege that pyridoxine neuropathy may occur after daily intake of as little as 75 milligrams (mg)/day (Dalton, 1985), although more common doses in symptomatic patients would be from 500 mg/day (Berger & Schaumberg, 1984) to 2000 mg/day (Waterston & Gilligan, 1987; McLachlan & Brown, 1995).
b) Sensory neuropathy, including paresthesias and reduced proprioception, occurred in 5 of 8 patients, who ingested 600 to 1200 milligrams/day of pyridoxine for years (Ludolph et al, 1993).
c) Pyridoxine can affect small neural fibers as well as large-diameter, heavily myelinated fibers, and neural symptoms can increase in intensity for weeks after discontinuation of pyridoxine administration (a phenomenon called COASTING). Five subjects self-administered toxic doses of pyridoxine until the first sign of sensory disturbance. Three subjects took 1 gram/day (low-dose) and 2 subjects took 3 grams/day (high-dose). Two low-dose subjects stopped pyridoxine treatment at 4.5 and 7 months when they manifested small neural fiber dysfunction. When the study terminated at 14 months, the third subject still had no symptoms. The plasma pyridoxine level of that subject remained at about 80 nanomoles (nmol), while those of subjects 1 and 2 were above 600 nmol. The high-dose subjects developed simultaneously small neural fiber and large-diameter myelinated fiber dysfunction, at 1.5 and 3.5 months. All subjects with neural manifestations experienced coasting after stopping pyridoxine administration (Berger et al, 1992).
d) Exacerbation of isoniazid-induced neuropathy by oral pyridoxine (150 milligrams daily) has been described in 1 case report (Nisar et al, 1990). The authors question the recommended use of high doses of pyridoxine to treat isoniazid related neuropathy.
e) One investigator found no reports of sensory PERIPHERAL NEUROPATHY in studies of patients with pyridoxine-dependency syndromes who were treated with pyridoxine 500 to 1500 milligrams daily (Bender, 1989a).

From the Micromedex. Sorry I can’t link you to it directly, but it’s a subscription service.

Best I can do for the moment, it may give you some leads to pursue.

[natlp]

Thanks so much!

@Qadgop the Mercotan

From the Micromedex. Sorry I can’t link you to it directly, but it’s a subscription service.

Best I can do for the moment, it may give you some leads to pursue.