New Study Identifies Vitamin K2 as a Novel Treatment for Nighttime Leg Cramps

From a natural perspective, magnesium has been consistently prescribed to help treat nighttime leg cramps. According to a newly published randomized clinical trial, vitamin K2 should also be considered.

The trial, which was published in JAMA Internal Medicine, randomly assigned 199 adults aged 65 or older to receive either 180 microgram (mcg) of vitamin K2 or placebo for eight weeks. The primary outcome was the number of nighttime leg cramps per week and the secondary outcomes were muscle cramp duration and severity. During the intervention, the vitamin K2 group experienced fewer cramps and had a significant reduction in both duration and severity compared to the placebo group.

These results are consistent with a 2022 multicenter, randomized, controlled, crossover pilot study conducted by this same research group showing that vitamin K2 prevented muscle cramps in hemodialysis patients. While the exact mechanisms regarding vitamin K’s effect on muscle are not clear, the researchers point out that “vitamin K causes myometrial relaxation by inhibiting calcium intake from the external medium, an action mediated by blocking the voltage-dependent calcium channels and thus attenuating intracellular calcium levels in muscle cells.”

“This study is intriguing and adds to the growing amount of research demonstrating the various important health benefits of vitamin K,” said John Neustadt, ND, author of the best-selling book Fracture-Proof Your Bones. “Initially it was thought that vitamin K was only helpful for blood clotting but more recently research shows that it is also essential for bone health, restoring cellular function in cancer, cardiovascular health, and brain function. The fact that it has been shown to help with muscle cramps is an exciting new role for this important vitamin.”

Vitamin K is a family of compounds including phylloquinone (vitamin K1) and a series of menaquinones (vitamin K2) including MK4 and MK7. The form of vitamin K2 used in this new study was MK7. Vitamin K1 and MK7 are transformed in the body into MK4, which is the predominant form of vitamin K2 that is found in the body.

Dr. Neustadt points out that utilizing the appropriate form of vitamin K2 is important.

“All clinical trials on osteoporosis where bone density is increased and fractures are decreased used MK4. MK4 is also more effective at inducing apoptosis in cancer cells and is the only form of vitamin K2 shown in clinical trials to improve outcomes in cancer patients,” explained Dr. Neustadt, who is the Founder and President of Nutritional Biochemistry, Inc (NBI). “The clinical benefits may be from the increase in MK4 created by MK7, not MK7 itself. Additional research is needed to answer this question.”

Regardless of the form of vitamin K2, thanks to this latest study, nighttime leg cramps can be added to the growing list of health benefits of this important group of compounds.