Skip to main content
Evidence-Based Supplement Research
Evidence-Based Supplement Research

Study Design

Type
Randomized Controlled Trial (RCT)
Sample size
n = 523
Population
41 patients with muscle cramps refractory to conventional interventions who were on maintenance HD
Methods
Multicenter, randomized, placebo-controlled, crossover clinical trial; each participant received vitamin K2 (360 µg/d) or placebo for two 4-wk phases, then crossed to the alternative arm for two 4-wk phases after a 2-wk washout
Blinding
Double-blind
Duration
4 weeks per phase, two phases per arm plus 2-week washout
Funding
Unclear
  • Large Human Trial

Objectives

Muscle cramps occur in 33% to 78% of patients with dialysis. The etiology of muscle cramps is poorly understood, and no clear evidence-based prevention or treatment strategies exist. Improved interventions are urgently needed. The aim of this study was to investigate the effect of vitamin K2 in reducing the frequency and severity of muscle cramps in hemodialysis (HD) patients.

Methods

This multicenter, randomized, placebo-controlled, crossover clinical trial was conducted from June 2019 to May 2020. Each participant received vitamin K2 (360 µg/d) or placebo for two 4-wk phases, and then crossed to the alternative arm for two 4-wk phases after a 2-wk washout. The primary endpoint was the frequency of muscle cramps during HD. The secondary endpoints were severity and duration of muscle cramps during HD.

Results

A total of 523 patients with maintenance HD were screened for muscle cramps, including 41 patients with muscle cramps refractory to conventional interventions, were enrolled. Nineteen patients in the vitamin K2-initial group and 20 in the placebo-initial group completed the protocol, and were included in the final analysis. Vitamin K2 reduced the frequency, duration, and severity of muscle cramps in HD patients (all P < 0.05). The frequency, duration, and severity of muscle cramps in HD patients increased again after crossing over to the placebo. There were no serious adverse events. One patient experienced gastrointestinal discomfort when taking vitamin K2.

Conclusions

This pilot trial demonstrated that vitamin K2 supplementation could decrease the frequency, duration, and severity of muscle cramps in HD patients.

Research Insights

Back to top