title: Low vitamin K intakes in community-dwelling elders at an early stage of Alzheimer's disease.
abstract: An increasing body of evidence points to a role for vitamin K in brain physiology through its participation in sphingolipid metabolism and biological activation of the vitamin K-dependent protein Gas6. One hypothesis is that vitamin K may also play a role in the pathogenesis of Alzheimer's disease. A recent study found that patients with early-stage Alzheimer's disease consumed less vitamin K than did cognitively intact control subjects. To learn more about the dietary intakes and food sources of vitamin K in these patients, a detailed analysis was conducted. Dietary vitamin K intakes were assessed from 5 nonconsecutive days of food records collected from 31 community-dwelling patients with early-stage Alzheimer's disease and in 31 age- and sex-matched cognitively intact control subjects. Mean vitamin K intake on a person-day basis was 63+/-90 microg/day in patients and 139+/-233 microg/day in control subjects. Vitamin K intakes were significantly less in participants with Alzheimer's disease (P<0.0001), even after adjusting for energy intakes (P=0.0003). Vegetables, fats, and fruits contributed more than 70% of total vitamin K intake in both groups. The main source of vitamin K was green vegetables, which contributed 33% and 49% to total intakes in patients and control subjects, respectively. This lower consumption of green vegetables in participants with Alzheimer's disease explained their lower vitamin K intakes overall. Despite their limitations, results are in line with the most recent research in both vitamin K and Alzheimer's disease and suggest a need to consider vitamin K in future investigations on the role of diet in Alzheimer's disease.
authors.affiliation: Département de Nutrition, Université de Montréal, Montréal, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Presse
authors.forename: Bryna
authors.initials: B
authors.lastname: Shatenstein
authors.forename: Marie-Jeanne
authors.initials: MJ
authors.lastname: Kergoat
authors.forename: Guylaine
authors.initials: G
authors.lastname: Ferland
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology* / Q000378:metabolism; D016022:Case-Control Studies; D004032:Diet; D015930:Diet Records; D005260:Female; D005504:Food Analysis; D006801:Humans; D008297:Male; D009751:Nutritional Requirements; D009752:Nutritional Status; D014675:Vegetables / Q000737:chemistry; D014812:Vitamin K / Q000008:administration & dosage* / Q000502:physiology
chemical_list: D014812:Vitamin K