Serum Vitamin K1 Inversely Linked to Fracture Risk in Postmenopausal Osteoporosis

Sarfaroj Khan 


September 23, 2020


  • Higher serum vitamin K1 (phylloquinone) concentration was associated with reduced risk of fracture in women with postmenopausal osteoporosis (PMO).

  • Hip geometry and mechanical strength parameters including cross-sectional area (CSA), cross-sectional moment of inertia (CSMI) and section modulus ‘Z’ at the narrow neck of femur (NN) were positively associated with vitamin K1.

Why this matters

  • Findings suggest that a higher intake of vitamin K may be required for maximal effect on bone compared with coagulation.

Study design

  • A cross-sectional study of 374 women with PMO (mean age, 68.7 [standard deviation [SD], 12.3] years).

  • Data on bone mineral density (BMD) at the lumbar spine (LS), total hip (TH) and femoral neck (FN) and hip structural analysis (HSA) parameters (n=263) were derived from dual-energy X-ray absorptiometry scans.

  • Vitamin K-dependent proteins including undercarboxylated prothrombin (PIVKA-II) and dephospho-uncarboxylated form of Matrix Gla Protein (dp-ucMGP) were assessed in a subgroup (n=130).

  • Funding: Royal Osteoporosis Society, UK.

Key results

  • Serum vitamin K1 was significantly lower in women with prevalent fractures vs those without (0.53 [SD, 0.41] μg/L vs 0.65 [SD, 0.66] μg/L; P=.04).

  • An inverse association was seen between serum vitamin K1 concentration and fracture risk (adjusted OR per μg/L increase in serum vitamin K1, 0.550; 95% CI, 0.310-0.978; P=.042)

  • No significant association was observed between serum vitamin K1 concentration and BMD at the LS, FN and TH.

  • Among the HSA parameters, serum vitamin K1 was positively linked with CSA (P=.02), CSMI (P=.028) and section modulus ‘Z’ (P=.02) at the narrow neck of femur.

  • Dp-ucMGP was detectable in 97 (75%) women with a lower serum vitamin K1 concentration of 0.26 [SD, 0.15] μg/L (P<.001), whereas PIVKA-II was above the clinical threshold in only 3.8% of women.


  • Causality could not be established because of the cross-sectional design.


Moore AE, Kim E, Dulnoan D, Dolan AL, Voong K, Ahmad I, Gorska R, Harrington DJ, Hampson G. Serum vitamin K1 (phylloquinone) is associated with fracture risk and hip strength in post-menopausal osteoporosis: a cross-sectional study. Bone. 2020 Sep 9 [Epub ahead of print]:115630. doi: 10.1016/j.bone.2020.115630. PMID: 32919111 View abstract

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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