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

unlabelledLifetime 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.

introductionVitamin K might have a role in the primary prevention of fractures, but uncertainties about its effectiveness and cost-effectiveness persist.

methodsWe 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).

resultsAdding 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.

conclusionsLifetime 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.