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

Abstract

Summary: Lifetime supplementation with vitamin K, vitamin D3, 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 D3 (800 IU/day) with calcium (1,200 mg/day), and vitamin K2 (45 mg/day) with vitamin D3 and calcium (at the same doses). An additional analysis explored replacing vitamin K2 with vitamin K1 (5 mg/day). Results: Adding vitamin K2 to vitamin D3 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 K1 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 D3, 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. © International Osteoporosis Foundation and National Osteoporosis Foundation 2012.