The Effects of Vitamin K2 on Recovery from Muscle-Damaging Resistance Exercise in Young and Older Adults: The TAKEOVER Randomized Controlled Trial.

Twelve weeks of vitamin K2 supplementation successfully increased circulating MK-7 levels in participants.

• Supplementation dose was 240 μg/day of menaquinone-7 (MK-7)
• Duration of supplementation was 12 weeks
• Increase in circulating MK-7 levels was statistically significant (P < 0.001)
• The comparator was placebo (cellulose) in a double-blind design

Vitamin K2 supplementation had no supplement × time effects for any of the primary recovery variables.

• Variables assessed included knee extensor maximal torque, functional ability, muscle soreness, and systemic blood markers of muscle damage and inflammation
• Measurements were taken before (0 h) and at 3, 24, 48, and 72 h postexercise
• No significant supplement × time interaction effects were found for any variable
• Data were analyzed using regression and mixed models

Significant three-way supplement × time × older age interaction effects were observed for electromechanical delay (EMD) and electromyography root mean square (RMS).

• EMD showed a significant supplement × time × older age interaction (P = 0.03)
• EMG RMS showed a significant supplement × time × older age interaction (P = 0.01)
• In older adults, after 12 weeks, EMD appeared lower at all time points in the vitamin K2 group
• In older adults, RMS appeared higher postexercise in the vitamin K2 group

Significant three-way supplement × time × older age interaction effects were observed for interleukin-6 (IL-6) and creatine kinase (CK) in older adults.

• IL-6 concentrations showed a significant supplement × time × older age interaction (P < 0.001)
• CK levels showed a significant supplement × time × older age interaction (P = 0.02)
• No clear overall pattern in IL-6 or CK was observed across all time points
• At 72 h postexercise, CK was lower in older adults in the vitamin K2 group

The study enrolled and completed data collection on 71 participants across young and older adult age groups.

• 71 participants completed the study
• 35 participants were young adults (18–40 years)
• 36 participants were older adults (65+ years)
• Participants were randomly assigned to vitamin K2 or placebo in a double-blind randomized controlled trial

Vitamin K2 supplementation had no effect on muscle strength, physical function, or muscle soreness during recovery from muscle-damaging resistance exercise.

• Knee extensor maximal torque was assessed as the primary measure of muscle strength
• Functional ability was assessed as a measure of physical function
• Muscle soreness was measured at 0, 3, 24, 48, and 72 h postexercise
• No supplement × time effects were found for these variables in either age group