Effect of Vitamin K2 on Postural Sway in Older People Who Fall: A Randomized Controlled Trial.

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.

Vitamin K supplementation for the primary prevention of osteoporotic fractures: is it cost-effective and is future research warranted?

UNLABELLED: Lifetime supplementation with vitamin K, vitamin D(3), and calcium is likely to reduce fractures and increase survival in postmenopausal women. It would be a cost-effective intervention at commonly used thresholds, but high uncertainty around the cost-effectiveness estimates persists. Further research on the effect of vitamin K on fractures is warranted. INTRODUCTION: Vitamin K might have a role in the primary prevention of fractures, but uncertainties about its effectiveness and cost-effectiveness persist. METHODS: We developed a state-transition probabilistic microsimulation model to quantify the cost-effectiveness of various interventions to prevent fractures in 50-year-old postmenopausal women without osteoporosis. We compared no supplementation, vitamin D(3) (800 IU/day) with calcium (1,200 mg/day), and vitamin K(2) (45 mg/day) with vitamin D(3) and calcium (at the same doses). An additional analysis explored replacing vitamin K(2) with vitamin K(1) (5 mg/day). RESULTS: Adding vitamin K(2) to vitamin D(3) with calcium reduced the lifetime probability of at least one fracture by 25%, increased discounted survival by 0.7 quality-adjusted life-years (QALYs) (95% credible interval (CrI) 0.2; 1.3) and discounted costs by $8,956, yielding an incremental cost-effectiveness ratio (ICER) of $12,268/QALY. At a $50,000/QALY threshold, the probability of cost-effectiveness was 95% and the population expected value of perfect information (EVPI) was $28.9 billion. Adding vitamin K(1) to vitamin D and calcium reduced the lifetime probability of at least one fracture by 20%, increased discounted survival by 0.4 QALYs (95% CrI -1.9; 1.4) and discounted costs by $4,014, yielding an ICER of $9,557/QALY. At a $50,000/QALY threshold, the probability of cost-effectiveness was 80% while the EVPI was $414.9 billion. The efficacy of vitamin K was the most important parameter in sensitivity analyses. CONCLUSIONS: Lifetime supplementation with vitamin K, vitamin D(3), and calcium is likely to reduce fractures and increase survival in postmenopausal women. Given high uncertainty around the cost-effectiveness estimates, further research on the efficacy of vitamin K on fractures is warranted.

Vitamin K to prevent fractures in older women: systematic review and economic evaluation.

OBJECTIVE: To determine the clinical and cost-effectiveness of vitamin K in preventing osteoporotic fractures in postmenopausal women. DATA SOURCES: Searches were conducted in May 2007 in MEDLINE, MEDLINE In-Process, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, BIOSIS, CINAHL, DARE, NHS EED and HTA databases, AMED, NRR, Science Citation Index and Current Controlled Trials. The MEDLINE search was updated in March 2009. REVIEW METHODS: Selected studies were assessed and subjected to data extraction and quality assessment using standard methods. Where appropriate, meta-analysis was carried out. A mathematical model was constructed to estimate the cost-effectiveness of vitamin K1. RESULTS: The electronic literature searches identified 1078 potentially relevant articles. Of these, 14 articles relating to five trials that compared vitamin K with a relevant comparator in postmenopausal women with osteoporosis or osteopenia met the review inclusion criteria. The double-blind ECKO trial compared 5 mg of phylloquinone (vitamin K1) with placebo in Canadian women with osteopenia but without osteoporosis. Four open-label trials used 45 mg of menatetrenone (vitamin K2) in Japanese women with osteoporosis; the comparators were no treatment, etidronate or calcium. The methodological quality of the ECKO trial was good; however, all four menatetrenone trials were poorly reported and three were very small (n < 100 in each group). Phylloquinone was associated with a statistically significant reduction in the risk of clinical fractures relative to placebo [relative risk 0.46, 95% confidence interval (CI) 0.22 to 0.99]; morphometric vertebral fractures were not reported. The smaller menatetrenone trials found that menatetrenone was associated with a reduced risk of morphometric vertebral fractures relative to no treatment or calcium; however, the larger Osteoporosis Fracture (OF) study found no evidence of a reduction in vertebral fracture risk. The three smaller trials found no significant difference between treatment groups in non-vertebral fracture incidence. In the ECKO trial, phylloquinone was not associated with an increase in adverse events. In the menatetrenone trials, adverse event reporting was generally poor; however, in the OF study, menatetrenone was associated with a significantly higher incidence of skin and skin appendage lesions. No published economic evaluations of vitamin K were found and a mathematical model was thus constructed to estimate the cost-effectiveness of vitamin K1. Comparators were alendronate, risedronate and strontium ranelate. Vitamin K1 and alendronate were markedly more cost-effective than either risedronate or strontium ranelate. The base-case results favoured vitamin K1, but this relied on many assumptions, particularly on the efficacy of preventing hip and vertebral fractures. Calculation of the expected value of sampled information was conducted assuming a randomised controlled trial of 5 years' duration comparing alendronate with vitamin K1. The costs incurred in obtaining updated efficacy data from a trial with 2000 women per arm were estimated to be a cost-effective use of resources. CONCLUSIONS: There is currently large uncertainty over whether vitamin K1 is more cost-effective than alendronate; further research is required. It is unlikely that the present prescribing policy (i.e. alendronate as first-line treatment) would be altered.