Past research studies have suggested that a low intake of vitamin K may be linked to an increased rate of bone fractures. Researchers in Japan recently examined numerous randomized, controlled trials to determine what role vitamin K supplementation might play in this association.

Adult participants in the studies were given either oral vitamin K supplements (phytonadione and menaquinone-4) or a placebo for at least 6 months. After conducting a meta-analysis of seven different studies, the researchers concluded that “supplementation with phytonadione and menaquinone-4 reduces bone loss.” Menaquinone-4 was especially useful in reducing the risk of vertebral and hip fractures in the Japanese subjects.