Research
Micronutrients & recovery
Vitamin D supplementation does NOT improve muscle strength (1-RM) or power in young athletes if serum levels do not exceed 40 ng/mL.
Don't expect Vitamin D to make you stronger if your levels are only 'normal'. If you are supplementing for performance, aim for >40 ng/mL. If your levels stay below 40 ng/mL, you likely won't see strength gains, even if you correct a deficiency.
ModerateRefutesMEDIUM confidence
Contrary to the findings in the elderly population, no significant improvements in muscle performance were observed after 6 or 12 weeks of vitamin D supplementation, although serum 25(OH)D levels significantly increased over this time, from an average of 20.43 ng/mL to 31.65–39.26 ng/mL
Why this rating
Based on a specific study (Close et al., 2013) with a moderate sample size (n=30) and specific dosing regimen.
Source
Vitamin D and the Athlete: Risks, Recommendations, and Benefits
Dana Ogan et al. · Nutrients · 2013
narrative_reviewCited 178×
Read the paper This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →