No effect of vitamin K1 intake on bone mineral density and fracture risk in perimenopausal women.

INTRODUCTION

Vitamin K functions as a co-factor in the post-translational carboxylation of several bone proteins, including osteocalcin.

AIM

The aim of this study was to investigate the relationship between vitamin K(1) intake and bone mineral density (BMD) and fracture risk in a perimenopausal Danish population.

DESIGN

The study was performed within the Danish Osteoporosis Prevention Study (DOPS), including a population-based cohort of 2,016 perimenopausal women. During the study approximately 50% of the women received hormone replacement therapy (HRT). Associations between vitamin K(1) intake and BMD were assessed at baseline and after 5-years of follow-up (cross-sectional design). Moreover, associations between vitamin K(1) intake and 5-year and 10-year changes in BMD were studied (follow-up design). Finally, fracture risk was assessed in relation to vitamin K(1) intake (nested case-control design).

RESULTS

In our cohort, dietary vitamin K(1) intake (60 mug/day) was close to the daily intake recommended by the Food and Agriculture Organization (FAO). Cross-sectional and longitudinal analyses showed no associations between intake of vitamin K(1) and BMD of the femoral neck or lumbar spine. Neither did BMD differ between those 5% that had the highest vitamin K(1) intake and those 5% that had the lowest. During the 10-years of follow-up, 360 subjects sustained a fracture (cases). In a comparison between the cases and 1,440 controls, logistic regression analyses revealed no difference in vitamin K(1) intake between cases and controls.

CONCLUSION

In a group of perimenopausal and early postmenopausal women, vitamin K(1) intake was not associated with effects on BMD or fracture risk.