They strike in the middle of the night without warning. A painful contraction of the calf muscle wrenches sleepers out of dreamland and throws them into a Greco-Roman wrestling match with an unseen opponent. The dreaded leg cramp has struck again.
Researchers led by the Third People's Hospital of Chengdu, China, found that vitamin K 2 supplementation reduces the frequency, intensity, and duration of nocturnal leg cramps (NLCs) in older individuals. Approximately 50% to 60% of adults experience NLCs (sometimes referred to as a Charley horse) in their lifetime, with about 20% encountering significant distress and insomnia that lead them to seek medical intervention. There are no medical treatments without a substantial list of unpleasant side effects.
In a paper, "Vitamin K 2 in Managing Nocturnal Leg Cramps: A Randomized Clinical Trial," published in JAMA Internal Medicine , the researchers investigated whether vitamin K 2 is better than a placebo in managing nocturnal leg cramps. Conducted in China, the multicenter, double-blind, placebo-controlled randomized clinical trial enrolled 199 individuals aged 65 years and older (mean age 72.3) who experienced two or more documented episodes of NLCs during a two-week screening period.
Participants were randomly assigned in a 1:1 ratio to receive either vitamin K 2 (menaquinone 7), 180 μg, or a placebo capsule daily for eight weeks. The study's primary outcome was the mean number of NLCs per week between the vitamin K 2 and placebo .