title: Vitamin K deficiency in children pre-bone marrow transplantation.
abstract: This study examined the prevalence of vitamin K deficiency in children pre-bone marrow transplantation (BMT). Vitamin K status was measured by the PIVKA-II assay and prothrombin times. Blood samples were obtained before vitamin-containing TPN was infused. Results indicated that eight of 26 patients (31%) were vitamin K deficient; four cases were attributed to drug antagonism (phenytoin) and four were due to inadequate vitamin K intake, synthesis or malabsorption. Only one patient had a prolonged prothrombin time. Prothrombin time, in our study, is shown to be an ineffective screening tool to determine vitamin K status. All patients receiving phenytoin and chemotherapy are at increased risk of vitamin K deficiency.
authors.affiliation: Division of Haematology/Oncology, Department of Clinical Dietetics, The Hospital for Sick Children, Toronto, Ontario, Canada. marry.baron@sickkids.ca
authors.forename: M A
authors.initials: MA
authors.lastname: Barron
authors.forename: J
authors.initials: J
authors.lastname: Doyle
authors.forename: S
authors.initials: S
authors.lastname: Zlotkin
mesh_terms: D000293:Adolescent; D000927:Anticonvulsants / Q000009:adverse effects / Q000037:antagonists & inhibitors; D016026:Bone Marrow Transplantation; D002648:Child; D002675:Child, Preschool; D004336:Drug Antagonism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000150:complications / Q000628:therapy; D010672:Phenytoin / Q000008:administration & dosage / Q000009:adverse effects; D015995:Prevalence; D011517:Prothrombin Time / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D014812:Vitamin K / Q000378:metabolism; D014813:Vitamin K Deficiency / Q000097:blood* / Q000453:epidemiology / Q000209:etiology
chemical_list: D000927:Anticonvulsants; D014812:Vitamin K; D010672:Phenytoin