Vitamin K₂ for Managing Nocturnal Leg Cramps

Few evidence-based treatment options are available for nocturnal leg cramps. In this Chinese trial, researchers evaluated the effectiveness of vitamin K₂ (menaquinone) for managing idiopathic nocturnal leg cramps in 200 people who were 65 or older. Participants were required to have had >2 episodes of cramps in the 2 weeks prior to enrollment; people with medical conditions and those taking medications associated with muscle cramps were excluded. Participants were randomized to receive 180 µg of vitamin K₂ or placebo daily for 8 weeks.

Mean nocturnal cramp frequency was significantly lower in the active-treatment group than in the placebo group (1.0 vs. 3.6 episodes weekly). Average duration and self-rated severity of cramps also decreased m…