Vitamin K2 reduces night leg cramps by 50% in large clinical trial
Around 40% of people over 50 experience night cramps - known by many names, such as sleep or nocturnal leg cramps (NLCs) - in which muscles in the lower limbs contract painfully and that can take up to several minutes to recede. However, only a minority of sufferers report them to their doctor.
Now, researchers from the Third People's Hospital in China and several medical colleges have found a promising preventer for these waking nightmares, and a clinical trial of 199 people found that vitamin K2 significantly reduced episodes, pain experienced and the duration of the cramping.
"This study was based on our previous research, which revealed the efficacy of vitamin K2 in relieving hemodialysis-related muscle cramps," the researchers noted. "To our knowledge, this is the first study that explored the use of vitamin K2 specifically for treating NLCs."
Until now, lifestyle interventions - exercise, hydration - have been an imperfect way to reduce the chances of experiencing frequent NLCs, which become more frequent as we age and are often independent of any underlying diseases or conditions. While magnesium supplements have shown some efficacy in relieving cramping in pregnant women, it didn't help NLCs in general.
Overall, while a less active lifestyle and poor diet and lifestyle plays a role in the condition, it's not well understood nor treated.
"Quinine has been shown to be effective in treating NLCs but is not recommended by the US Food and Drug Administration due to severe side effects," the researchers noted in a preliminary study protocol paper last year. "Magnesium supplements are often used as a preventative treatment for NLCs; however, their effectiveness is controversial."
Controversial, because trials have not delivered clinically significant results for older adults who experience NLCs.
In this eight-week study, 199 participants aged 65 or older with a minimum of two NLCs in two weeks were recruited for a randomized, double-blind, placebo-controlled trial to test whether vitamin K2 could be a better intervention.
Splitting the group in two, 103 participants were randomly assigned to take a daily dose of 180 μg of K2, with the remaining 96 people receiving the placebo. Overall, 54% were female and the average age was 72.