Vitamin D and athletic performance in athletes
What it found
In athletes, vitamin D deficiency was common in some groups, and supplements raised blood levels.
Whether that improves performance is still unclear.
What they found
Studies in people
Soccer players' levels
In young soccer players, daily cholecalciferol for two months raised vitamin D plasma concentration by 92%. Another study found a 119% rise in a supplemented group and an 8.4% drop in a non-supplemented group during eight weeks of high-intensity training.
Volleyball players' levels
Among male professional volleyball players, 27% had vitamin D deficiency, 46% were insufficient, and 27% were sufficient. Vitamin D level did not relate to shoulder muscle strength.
Sprint and jump tests
Young soccer players with low vitamin D levels (below 30 ng/mL) and those with higher levels (61-130 ng/mL) showed no difference in 5, 15, and 30 metre sprint tests or the standing long jump test. In the low-level group, daily supplements for two months raised vitamin D concentration by 79.2%.
Diabetes and exercise
In boys with type 1 diabetes, those with vitamin D deficiency had likely higher blood sugar variability during days of exercise training than those with a suboptimal level.
Measuring vitamin D intake
A questionnaire to assess vitamin D intake and lifestyle factors was checked against serum 25(OH)D concentrations and 7-day food diaries. The authors highlighted the difficulty of using intake methods for vitamin D, as its status is influenced by body size and dietary sources.
Studies in people and animals
Muscle and immune function
One review concluded that vitamin D deficiency may cause deficits in strength and lead to degeneration of type II muscle fibers, which has been found to negatively correlate with physical performance. Another review concluded that vitamin D plasma concentration was associated with muscle function and immune response in both general and athletic populations.
What the authors conclude
- They hope this special issue will help raise awareness of current trends in vitamin D prevalence and supplementation.
- They advise that practitioners working with athletes should encourage them to be screened regularly for plasma concentration of vitamin D level.
- They expect the articles to trigger further research about the relationship of vitamin D with sport performance.
How it was done
The authors wanted to learn how common vitamin D deficiency is in different sports and whether giving supplements to athletes who lack vitamin D can improve their performance.
They put together a special issue with two reviews and six original studies. The studies looked at soccer and volleyball players, and boys with type 1 diabetes, checking vitamin D levels, supplements, and performance measures.
What it can’t tell you
- Most of the findings come from small groups of athletes in specific sports, so they may not apply to all people or all sports.
- The studies measured vitamin D levels and performance at the same time or after supplements, but they cannot prove that vitamin D directly causes better performance.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- University of Zurich, Switzerland; Exercise Physiology Laboratory, Greece; University of West Attica, Greece
The paper
- Title
- Vitamin D and Sport Performance
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Knechtle B, Nikolaidis PT (2020). Vitamin D and Sport Performance. Nutrients. doi:10.3390/nu12030841Free full textPubMed 32245151DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error