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Serum vitamin K1 inversely related to fracture risk in postmenopausal osteoporosis

Publish date:: November 5, 2020

Key clinical point: Higher serum vitamin K1 (phylloquinone) concentration is associated with a reduced risk for fracture in women with postmenopausal osteoporosis (PMO).

Major finding: Serum vitamin K1 was significantly lower in women with prevalent fractures vs. those without (0.53 μg/L vs. 0.65 μg/L; P = .04). Vitamin K1 inversely correlated with fracture risk (adjusted odds ratio per μg/L increase in serum vitamin K1, 0.550; P = .042). Hip geometry and mechanical strength parameters including cross-sectional area, cross-sectional moment of inertia, and section modulus ‘Z’ at the narrow neck of femur were positively associated with vitamin K1.

Study details: The data come from a cross-sectional study of 374 women with PMO (mean age, 68.7 years).

Disclosures: The study was funded, in part, by the Royal Osteoporosis Society, U.K. The authors declared no conflicts of interest.

Commentary

“Vitamin K is thought to have skeletal effects, but the association between vitamin K1 and fractures is poorly defined. This cross sectional study involved 374 community-dwelling women with osteoporosis who were seen in a specialized osteoporosis clinic in London, UK. In this sample, 251 (67%) women had experience fractured. Serum vitamin K1 level was obtained during the visit and was lower among women who had past fractures. This finding remained statistically significant after adjusting for potential confounders including age, bone mass index, vitamin D level, smoking and alcohol use habits. Higher levels of vitamin K1 were associated with lower fracture risk.

Since measures of hip geometry and mechanical strength parameters were associated with vitamin K1 level, it appears that vitamin K1 may reduce fracture risk through its role on improving bone strength. This study provides evidence for the role of vitamin K1 in bone health, but since the racial/ethnic composition of the sample is not described, whether these findings are generalizable is unclear. In addition, men were not studied and future studies involving men are also needed.”