title: Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk.
abstract: Increasing evidence indicates a significant role for vitamin K in bone metabolism and osteoporosis. In this study, we found a large geographic difference in serum vitamin K2 (menaquinone-7; MK-7) levels in postmenopausal women. Serum MK-7 concentrations were 5.26 +/- 6.13 ng/mL (mean +/- SD) in Japanese women in Tokyo, 1.22 +/- 1.85 in Japanese women in Hiroshima, and 0.37 +/- 0.20 in British women. We investigated the effect of Japanese fermented soybean food, natto, on serum vitamin K levels. Natto contains a large amount of MK-7 and is eaten frequently in eastern (Tokyo) but seldom in western (Hiroshima) Japan. Serum concentrations of MK-7 were significantly higher in frequent natto eaters, and natto intake resulted in a marked, sustained increase in serum MK-7 concentration. We analyzed the relation between the regional difference in natto intake and fracture incidence. A statistically significant inverse correlation was found between incidence of hip fractures in women and natto consumption in each prefecture throughout Japan. These findings indicate that the large geographic difference in MK-7 levels may be ascribed, at least in part, to natto intake and suggest the possibility that higher MK-7 level resulting from natto consumption may contribute to the relatively lower fracture risk in Japanese women.
authors.affiliation: Department of Geriatric Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kaneki
authors.forename: S J
authors.initials: SJ
authors.lastname: Hodges
authors.forename: S J
authors.initials: SJ
authors.lastname: Hedges
authors.forename: T
authors.initials: T
authors.lastname: Hosoi
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: A
authors.initials: A
authors.lastname: Lyons
authors.forename: S J
authors.initials: SJ
authors.lastname: Crean
authors.forename: N
authors.initials: N
authors.lastname: Ishida
authors.forename: M
authors.initials: M
authors.lastname: Nakagawa
authors.forename: M
authors.initials: M
authors.lastname: Takechi
authors.forename: Y
authors.initials: Y
authors.lastname: Sano
authors.forename: Y
authors.initials: Y
authors.lastname: Mizuno
authors.forename: S
authors.initials: S
authors.lastname: Hoshino
authors.forename: M
authors.initials: M
authors.lastname: Miyao
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Horiki
authors.forename: M
authors.initials: M
authors.lastname: Shiraki
authors.forename: Y
authors.initials: Y
authors.lastname: Ouchi
authors.forename: H
authors.initials: H
authors.lastname: Orimo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001407:Bacillus / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D005265:Femoral Neck Fractures / Q000453:epidemiology*; D005285:Fermentation; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000209:etiology* / Q000517:prevention & control; D012307:Risk Factors; D013025:Glycine max / Q000737:chemistry* / Q000378:metabolism; D014280:Triglycerides / Q000097:blood; D006113:United Kingdom / Q000453:epidemiology; D010837:Vitamin K 1 / Q000097:blood; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D014280:Triglycerides; D024482:Vitamin K 2; D010837:Vitamin K 1; C062629:menaquinone 7