Can vitamin d give athletes an edge? new trial investigates
NCT ID NCT07641075
First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This study gives 200 athletes either high-dose vitamin D3 (4,000 IU daily) or a placebo for 4 to 8 weeks. Researchers measure changes in vitamin D levels, hormones, muscle function, cognitive performance, and body composition. The goal is to see if extra vitamin D improves athletic and mental performance in well-trained individuals.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Vitamin D3 (cholecalciferol)
- What this could lead to
- If it works, this could show that vitamin D boosts athletic performance, cognitive function, and body composition in trained athletes.
- What could go wrong
- This is a small, early-stage study in healthy athletes, so results may not apply to the general public. High-dose vitamin D can cause side effects like high calcium levels, though 4,000 IU is generally safe.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
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About 200 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Jul 2025
- Expected to finish
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Dec 2028
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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17 to 60 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * a minimum of 8 years of training experience, * absence of injuries in the 6 months leading up to the assessments, * consistent engagement in training sessions a minimum of 5 times per week over the last 6 months. Exclusion Criteria: * vitamin D supplementation within one month prior to the study, * use of multivitamin supplements, * intestinal disorders.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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The Jerzy Kukuczka Academy of Physical Education in Katowice
RECRUITINGKatowice, Mikołowska 72a, 40-065, Poland
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