title: Plasma vitamin K concentration in horses supplemented with several vitamin K homologs.
abstract: The effect of several vitamin K homologs on plasma vitamin K concentration was determined to assess their potential as a vitamin K supplement for adult horses. Sixteen Thoroughbred horses consisting of 8 mares and 8 geldings, aged 8.4 ± 3.6 yr and weighing 520.8 ± 36.1 kg, were allocated to 4 groups (n = 4). Each group was given phylloquinone, menaquinone-4, or menadione at 58 µmol/d, or no vitamin K supplement for 7 d. Plasma samples were collected before feeding, and 2, 4, and 8 h after feeding on d 7, and plasma concentrations of phylloquinone and menaquinone-4 were determined. Plasma phylloquinone concentration was greater in the phylloquinone group than in the other groups (P < 0.001). The phylloquinone concentration quadratically increased (P < 0.001) after feeding in the phylloquinone group but no changes in the plasma phylloquinone concentration were observed after feeding in the other groups. Plasma menaquinone-4 concentration was greater (P < 0.001) in the menadione group than the other groups, including the menaquinone-4 group. Menaquinone-4 concentration did not change (P = 0.192) after feeding in each group. Menaquinone-4 has been considered the most potent vitamin K homolog for bone metabolism; therefore, the present experiment indicates that menadione is a good source of vitamin K for bone health in horses because it is the only vitamin K homolog that increased the plasma concentrations of menaquinone-4.
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Terachi
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: N
authors.initials: N
authors.lastname: Ashihara
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Ando
authors.forename: T
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements / Q000032:analysis*; D005260:Female; D006736:Horses / Q000378:metabolism*; D008297:Male; D014812:Vitamin K / Q000097:blood* / Q000378:metabolism*; D010837:Vitamin K 1 / Q000097:blood / Q000378:metabolism; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D024483:Vitamin K 3 / Q000378:metabolism
chemical_list: D024482:Vitamin K 2; D014812:Vitamin K; C030814:menatetrenone; D024483:Vitamin K 3; D010837:Vitamin K 1