title: Chronic idiopathic axonal polyneuropathy and vitamin B6: a controlled population-based study.
abstract: Vitamin B6 intoxication can result in a sensory ataxic neuropathy, but the association with a milder predominantly sensory or sensorimotor phenotype in chronic idiopathic axonal polyneuropathy (CIAP) remains unclear. A total of 381 patients with CIAP and 140 healthy controls were prospectively included. In a standardized fashion the use of vitamin B6 containing supplements and vitamin B6 levels were compared between patients and controls. On follow-up, patients were questioned about cessation of supplement use and the impact on the symptoms of polyneuropathy. Vitamin B6 levels in patients (median: 99 nmol/l, range: 38-2,967 nmol) were not significantly higher than in controls (median: 109 nmol/l, range: 41-2,373 nmol/l, p = 0.58), nor were daily dose, cumulative dose or duration of supplement use. However, more patients (31%) than controls (22%) used vitamin B6 containing supplements (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.0-2.7, p = 0.032). Follow-up of patients confirming the cessation of supplements showed slow progression of symptoms in 64%, stabilization in 26%, and regression in 10%. On the basis of our prospective case-control study and review of the literature, an association between CIAP and vitamin B6 exposure or elevated vitamin B6 levels appears unlikely.
authors.affiliation: Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Nora A
authors.initials: NA
authors.lastname: Visser
authors.forename: Nicolette C
authors.initials: NC
authors.lastname: Notermans
authors.forename: Lieveke A R
authors.initials: LA
authors.lastname: Degen
authors.forename: Jelle R
authors.initials: JR
authors.lastname: de Kruijk
authors.forename: Leonard H
authors.initials: LH
authors.lastname: van den Berg
authors.forename: Alexander F J E
authors.initials: AF
authors.lastname: Vrancken
mesh_terms: D000368:Aged; D002908:Chronic Disease; D018672:Community Health Planning; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011115:Polyneuropathies / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D025101:Vitamin B 6 / Q000009:adverse effects* / Q000378:metabolism*
chemical_list: D025101:Vitamin B 6
keywords: polyneuropathy; pyridoxine; vitamin B6