BACKGROUND AND PURPOSE:

• Data on the effects of vitamin D supplementation and omega-3 fatty acids on muscle mass and physical performance has been inconsistent
• Chou et al. (The Journal of Clinical Endocrinology & Metabolism, 2024) examined whether supplementation with vitamin D₃ or omega-3 fatty acids vs placebo improves physical performance measures

METHODS:

• Ancillary study of a double-blind placebo-controlled randomized trial
  • Parent RCT: VITamin D and OmegA-3 TriaL (VITAL)
    • Primary endpoints: No change in CVD or cancer outcomes
• Participants
  • Men ≥50 years and women ≥55 years
  • 2 years follow-up
• Interventions
  • Supplemental vitamin D₃ (cholecalciferol, 2000 IU/day)
  • Supplemental omega-3 fatty acids (1 g/day)
  • Placebo
• Study design
  • Participants were randomized to interventions using a 2×2 factorial design
• Primary outcomes
  • 2-year changes in physical performance measures
    • Grip strength | Walking speed | Standing balance | Repeated chair stands | Timed-up and Go (TUG) test

RESULTS:

• 1054 adults
• At the 2-year follow-up, all groups, supplemented and placebo, had worse walking speed and TUG
• When comparing vitamin D to placebo, or omega-3 to placebo, there were no changes in
  • Grip strength
  • Walking speed
  • Short Physical Performance Battery (composite of walking speed, balance, and chair stands)
  • TUG
• There were no differences in effect by
  • Sex | Age | BMI | Baseline total or free 25-hydroxyvitamin D (25[OH]D) or plasma omega-3 index
• TUG became slightly worse with vitamin D supplementation, compared to placebo, in participants with baseline total 25(OH)D levels above the median
  • P=0.01 | P_interaction=0.04

CONCLUSION:

• In a healthy mid-life US adult population, vitamin D and omega-3 supplementation for 2 years had no effect on physical performance measures
• The authors state

These findings do not support supplementation with vitamin D or omega-3 acids for muscular health in the general population

Along with other findings from VITAL, these data suggest that public health guidelines should recommend against vitamin D supplementation for the prevention of adverse musculoskeletal health outcomes in healthy midlife to older adults

Learn More – Primary Sources:

Effects of Supplemental Vitamin D3, Omega-3 Fatty Acids on Physical Performance Measures in the VITamin D and OmegA-3 TriaL