Vitamin K2 reduces the frequency, intensity and duration of nighttime leg cramps.

The results show that the vitamin is effective and safe for the treatment of NLC in people over 65 years of age.

In a recent study published in JAMA Internal MedicineResearchers have studied the effects of vitamin K₂ on the severity, duration and frequency of night leg cramps (NLTS) in older people.

Background

Between 60 and 70% of adults experience NLC at some point, with approximately 20% reporting severe symptoms that can cause stress and affect their sleep, leading them to seek medical help.

There is limited evidence of the effectiveness of medications such as calcium channel blockers or magnesium in relieving symptoms. Quinine, although effective, is not recommended due to serious side effects, while other treatments lack evidence of effectiveness or safety, leading to problems in primary care.

Previous studies found vitamin K₂ to be a safe and effective therapy for reducing muscle spasms experienced by people on dialysis, indicating its potential for alleviating symptoms of LNC.

About the study

In this study, researchers conducted a randomized, double-blind, placebo-controlled clinical trial in two hospitals in China.

Participants were over 65 years of age and had experienced at least two episodes of NLC in the two weeks prior to recruitment. People who had recently taken vitamin K2, had malignancies, metabolic diseases, or other specific diseases were excluded from screening, and eligibility was confirmed by medical examination.

Half of the participants with a confirmed diagnosis were randomly assigned to receive a daily dose of 180 mcg of vitamin K._2, while the rest received a placebo for eight weeks. Placebo and vitamin K₂ the capsules were identical in appearance and packaging, and neither study personnel nor participants were aware of group assignment.

Participants took one capsule per night and were monitored for NLC events, pain level, and duration. Study staff contacted them weekly to ensure adherence, collect reports, and inquire about side effects.

The primary outcome was the average number of NLCs occurring each week during the eight-week study, with severity (on a scale of 1 to 10) and duration of seizures in minutes as secondary outcomes.

Conclusions

After screening for eligibility, the study included 199 participants with a mean age of 72.3 years, of whom just over 54% were women. Ninety-six people were given a placebo and 103 received vitamin K.₂ capsules. Compliance was high, 86–92% in both groups.

The groups were similar in terms of baseline characteristics and also experienced similar seizure frequencies initially, with intervention groups reporting 2.6 events per week and those receiving placebo reporting 2.71.

However, the group receiving vitamin K₂ reported that their average seizure frequency decreased to 0.96 events per week over eight weeks, while the average number of events in the placebo group increased to 3.63. Statistical tests determined that this difference was significant.

Those who received the vitamin capsule also reported greater reductions in pain severity and duration of NLC events. Participants did not report any side effects associated with vitamin K consumption.₂.

Conclusions

NLCs are common but currently difficult to treat because their causes remain unclear and safe and effective treatments are scarce. When developing new treatments, minimizing harm is critical.

According to previous data, vitamin K₂ relieves cramps associated with hemodialysis, researchers studied whether they could relieve the discomfort of NLC. They found that from the first week of the study, vitamin K₂ reduced the intensity, duration and frequency of NLC events. The mechanism may be a decrease in calcium levels, which leads to muscle relaxation.

Encouragingly, the therapy appeared to be safe in older adults, with no side effects reported during the study. However, it is not recommended for people taking certain blood thinners as it may affect how they work.

The researchers did not assess sleep or quality of life as an impact because this could reduce compliance and participation in the study. Additionally, all participants experienced mild symptoms of NLC, and further research is needed to find out whether supplements can relieve more severe cramps.

In conclusion, vitamin K₂ demonstrates the potential to safely and effectively reduce the symptoms of NLC, supporting further research assessing its impact on sleep quality and overall quality of life for those experiencing these phenomena.