Ethnic differences in osteocalcin gamma-carboxylation, plasma phylloquinone (vitamin K1) and apolipoprotein E genotype

Eur J Clin Nutr. 2005 Jan;59(1):72-81. doi: 10.1038/sj.ejcn.1602037.


Objective: To investigate plasma osteocalcin gamma-carboxylation and its relationship to plasma phylloquinone concentration and apolipoprotein E (apoE) genotype in women from three ethnic groups with differing osteoporotic fracture risk.

Design and subjects: Fasted blood samples were collected from postmenopausal Gambian (n=50), British (n=31) and Chinese women (n=23), and 11 premenopausal women in each group from three cross-sectional studies.

Results: After adjustment for total osteocalcin, plasma undercarboxylated osteocalcin (adjusted ucOC) was lowest in Chinese and highest in British women postmenopause (British vs Chinese 103% higher, P<0.0001; Gambian vs Chinese 66% higher, P<0.01). No differences were observed premenopause. Within each ethnic group, adjusted ucOC was similar pre- and postmenopause. Postmenopause, plasma phylloquinone was higher in Chinese women (1.0 ng/ml) than in British (0.31 ng/ml) and Gambian women (0.36 ng/ml) (P<0.0001). Premenopause, plasma phylloquinone was higher in Gambian and Chinese women (0.6 ng/ml) than in British women (0.3 ng/ml; P=0.01). Plasma phylloquinone and adjusted ucOC were inversely related in postmenopausal British women (R2=32.4%; P=0.0008). ApoE4 frequency was Gambian 32.6%, British 13.8% and Chinese 6%. A lower adjusted ucOC was associated with apoE2 genotype in British and Chinese women. Ethnic differences in adjusted ucOC persisted after adjustment for phylloquinone and apoE genotype.

Conclusion: These preliminary data indicate suboptimal vitamin K status in postmenopausal British compared to Chinese and Gambian women. Ethnic differences in apoE genotype may also influence osteocalcin gamma-carboxylation status. The study highlights the need for larger epidemiological investigations of ethnic differences in vitamin K status and the possible implications to bone health.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antifibrinolytic Agents / blood*
  • Apolipoproteins E / genetics*
  • China / ethnology
  • Cross-Sectional Studies
  • England / ethnology
  • Female
  • Gambia / ethnology
  • Genotype
  • Humans
  • Middle Aged
  • Osteocalcin / blood
  • Osteocalcin / metabolism*
  • Osteoporosis, Postmenopausal / epidemiology*
  • Osteoporosis, Postmenopausal / ethnology*
  • Osteoporosis, Postmenopausal / metabolism
  • Postmenopause / ethnology
  • Postmenopause / metabolism
  • Premenopause / ethnology
  • Premenopause / metabolism
  • Risk Factors
  • Vitamin K 1 / administration & dosage
  • Vitamin K 1 / blood*


  • Antifibrinolytic Agents
  • Apolipoproteins E
  • Osteocalcin
  • Vitamin K 1