Seniors taking vitamin K₂ experienced a statistically significant reduction in weekly nocturnal leg cramps compared to those on placebo, with cramp frequency decreasing from 2.60 to 0.96 per week, according to a recent randomized clinical trial.

Researchers evaluated vitamin K₂'s efficacy in managing nocturnal leg cramps (NLCs) in adults aged 65 and older. The study involved 199 participants who reported two or more NLC episodes during a two-week screening period. Participants were randomized to receive either vitamin K₂ (180 µg) or a placebo daily for eight weeks.

The primary outcome, mean weekly cramp frequency, showed a statistically significant reduction in the vitamin K₂ group compared to the placebo group. Baseline cramp frequencies were similar between groups, with means of 2.60 (vitamin K₂) and 2.71 (placebo). After eight weeks, the mean weekly cramp frequency decreased to 0.96 in the vitamin K₂ group, whereas the placebo group maintained a mean of 3.63 (difference, −2.67; 95% confidence interval, −2.86 to −2.49; P < .001).

Secondary outcomes assessed cramp duration and severity. Patients receiving vitamin K₂ experienced greater reductions in both severity (−2.55 points versus −1.24 points in placebo) and duration (−0.90 minutes versus −0.32 minutes in placebo). No adverse effects associated with vitamin K₂ use were reported in the study.

These findings, published in JAMA Internal Medicine, indicate that vitamin K₂ was associated with reduced cramp frequency, severity, and duration among older adults with NLCs. Limitations include the absence of quality-of-life or sleep metrics. Future studies are needed to assess these parameters to provide a more comprehensive understanding of vitamin K₂’s effects on NLC management.

Conflict of interest disclosures and funding sources are detailed in the full study publication.