title: Vitamin B(12) and methylmalonic acid levels in patients presenting with polyneuropathy.
abstract: This study was designed to determine the prevalence of definite vitamin B(12) deficiency (defined as < or =240 pg/ml) and possible vitamin B(12) deficiency (defined as >240 pg/ml and a methylmalonic acid [MMA] level >243 nmol/L) in patients with polyneuropathy and to determine whether patients in both groups respond to vitamin B(12) repletion. We performed a retrospective cohort study of 581 patients presenting with polyneuropathy over a 2-year period; 4% had definite vitamin B(12) deficiency and 32% had possible deficiency as the sole or contributing cause for their polyneuropathy. For those who received treatment with vitamin B(12), subjective improvement was seen in 87% with definite and in 43% with possible deficiency. Possible vitamin B(12) deficiency, defined as an elevated MMA level, is a common finding in patients with polyneuropathy and treatment of these patients with vitamin B(12) may lead to clinical improvement.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, E/CC 810, Boston, MA 02215, USA. rnardin@bidmc.harvard.edu
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Nardin
authors.forename: Amy N H
authors.initials: AN
authors.lastname: Amick
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Raynor
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood* / Q000627:therapeutic use*; D011115:Polyneuropathies / Q000097:blood* / Q000178:diet therapy*; D012189:Retrospective Studies; D014805:Vitamin B 12 / Q000097:blood* / Q000627:therapeutic use*
chemical_list: D008764:Methylmalonic Acid; D014805:Vitamin B 12