Vitamin K2 Supplementation Effective in Reducing Nocturnal Leg Cramps in Older Adults, New Trial Shows

The study, published in JAMA Internal Medicine, showed that vitamin K2 supplementation notably decreased the frequency, intensity, and duration of nocturnal leg cramps in older adults, demonstrating a strong safety profile.

Nocturnal leg cramps can significantly disrupt sleep and quality of life, impacting daily activities and overall well-being. With limited traditional treatment options available and no reliably safe and effective therapies currently established, researchers are increasingly exploring alternative solutions, including dietary supplements, to manage these cramps. Finding effective methods for alleviating nocturnal leg cramps is, therefore, essential.

Against the above background, Jing Tan, The Third People’s Hospital of Chengdu, Chengdu, China, and colleagues aimed to assess whether vitamin K2 is more effective than a placebo in managing nocturnal leg cramps.

For this purpose, the researchers conducted a multicenter, double-blind, placebo-controlled, randomized clinical trial in China from September 2022 to December 2023. The study involved community-dwelling individuals aged 65 and older with two or more documented nocturnal leg cramps during a two-week screening. Eligible participants were randomly assigned in a 1:1 ratio to receive either 180 μg of vitamin K2 (menaquinone 7) or a placebo for eight weeks.

The primary outcome measured was the mean number of NLCs per week, while secondary outcomes included the duration and severity of cramps.

The following were the key findings of the study:

• Among 310 participants, 111 were excluded from the study.
• Of the 199 enrolled individuals, 54.3% were female, with a mean age of 72.3 years.
• Participants were randomly assigned to two groups: 103 received vitamin K2, and 96 received a placebo.
• The mean baseline weekly frequency of cramps was similar for both groups: 2.60 for vitamin K2 and 2.71 for placebo.
• After the 8-week intervention, the vitamin K2 group reported a reduced mean weekly frequency of cramps to 0.96, while the placebo group maintained a frequency of 3.63.
• The statistically significant difference between groups was −2.67.
• The vitamin K2 group showed a greater mean reduction in NLC severity (−2.55 points) than the placebo group (−1.24 points).
• The vitamin K2 group also experienced a more significant mean decrease in the duration of NLCs (−0.90 minutes) than the placebo group (−0.32 minutes).
• There were no adverse events related to vitamin K2 supplementation.

This randomized clinical trial showed that vitamin K2 supplementation significantly decreased the frequency, intensity, and duration of nocturnal leg cramps in older adults, with a favorable safety profile.

"Given its safety, further clinical trials are recommended to confirm the effectiveness of vitamin K2 in managing cramps and to evaluate its impact on the quality of life and sleep in patients experiencing nocturnal leg cramps," the researchers concluded.

Reference:

Tan J, Zhu R, Li Y, et al. Vitamin K2 in Managing Nocturnal Leg Cramps: A Randomized Clinical Trial. JAMA Intern Med. Published online October 28, 2024. doi:10.1001/jamainternmed.2024.5726