The National Institute for Health Research Health Technology Assessment (NIHR HTA) programme has published a systematic review and economic evaluation of vitamin K in preventing osteoporotic fractures in postmenopausal women.

Details of the search strategy, included studies, and limitations can be viewed at the link below.  In summary the main findings were as follows:

• The double-blind ECKO trial found that phylloquinone (vitamin K1) 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 three smaller (n < 100 in each group) menatetrenone (vitamin K2) open-label 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. Vitamin K1 and alendronate were markedly more cost-effective than either risedronate or strontium ranelate.

The authors concluded that since there is large uncertainty over whether vitamin K1 is more cost-effective than alendronate (first line treatment), it is unlikely that the present prescribing policy would be altered.