RESUMO
OBJECTIVES: Vitamin K is thought to be involved in both bone health and maintenance of neuromuscular function. We tested the effect of vitamin K2 supplementation on postural sway, falls, healthcare costs, and indices of physical function in older people at risk of falls. DESIGN: Parallel-group double-blind randomized placebo-controlled trial. SETTING: Fourteen primary care practices in Scotland, UK. PARTICIPANTS: A total of 95 community-dwelling participants aged 65 and older with at least two falls, or one injurious fall, in the previous year. INTERVENTION: Once/day placebo, 200 µg or 400 µg of oral vitamin K2 for 1 year. MEASUREMENTS: The primary outcome was anteroposterior sway measured using sway plates at 12 months, adjusted for baseline. Secondary outcomes included the Short Physical Performance Battery, Berg Balance Scale, Timed Up & Go Test, quality of life, health and social care costs, falls, and adverse events. RESULTS: Mean participant age was 75 (standard deviation [SD] = 7) years. Overall, 58 of 95 (61%) were female; 77 of 95 (81%) attended the 12-month visit. No significant effect of either vitamin K2 dose was seen on the primary outcome of anteroposterior sway (200 µg vs placebo: -.19 cm [95% confidence interval [CI] -.68 to .30; P = .44]; 400 µg vs placebo: .17 cm [95% CI -.33 to .66; P = .50]; or 400 µg vs 200 µg: .36 cm [95% CI -.11 to .83; P = .14]). Adjusted falls rates were similar in each group. No significant treatment effects were seen for other measures of sway or secondary outcomes. Costs were higher in both vitamin K2 arms than in the placebo arm. CONCLUSION: Oral vitamin K2 supplementation did not improve postural sway or physical function in older people at risk of falls. J Am Geriatr Soc 67:2102-2107, 2019.