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
DOI 10.3390/nu5061856
narrative_reviewCited 178×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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- Vitamin D supplementation (1000–5000 IU/day) prevents stress fractures in active populations by optimizing bone mineral density and calcium absorption.Good
- Vitamin D supplementation improves anaerobic performance metrics (sprint time, vertical jump) in young athletes ONLY when serum levels exceed 40 ng/mL.Moderate
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