High-Dose Vitamin D Supplementation and Exercise Effects on Vitamin D Metabolites in Professional Football Players
NCT ID: NCT07310329
Last Updated: 2025-12-30
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
COMPLETED
NA
20 participants
INTERVENTIONAL
2024-04-27
2024-06-24
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
Twenty professional football players from a Polish top-division club participated in the study. Participants were randomly assigned to either the supplementation group (SGP) receiving 500,000 IU of vitamin D₃ or the placebo group (PGP) receiving an identical volume of placebo oil. The intervention was administered 48 hours prior to an intra-squad game. Blood samples were collected at three time points: baseline (T3), pre-match (T4), and post-match (T5). The primary outcome was the change in serum 25-(OH)D₃ concentration. Secondary outcomes included changes in 24,25-(OH)₂D₃ and 3-epi-25-(OH)D₃ levels, as well as their ratios. The study also assessed whether physical exercise modulates vitamin D metabolism.
The findings demonstrated that high-dose vitamin D₃ supplementation significantly increased serum 25-(OH)D₃ (↑198%) and 3-epi-25-(OH)D₃ (↑444%) levels, while football-specific exercise itself induced moderate increases in vitamin D metabolites. The results suggest that skeletal muscle may play a key role in vitamin D storage and release in response to exercise. The supplementation was well tolerated, with no adverse events observed.
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
Study Design
The study employed a randomized, single-blind, placebo-controlled, parallel-group design. Participants were randomly assigned to one of two groups:
Supplementation Group (SGP) - received a single oral dose of 500,000 IU vitamin D₃ (Vigantol Oil, P\&G Health, Germany);
Placebo Group (PGP) - received an identical amount of placebo (vegetable oil).
The supplementation was administered 48 hours before a standardized intra-squad football match (ISG), conducted under conditions simulating a competitive game. All players followed the same training schedule and diet during the study.
Participants
A total of 20 professional male football players (aged 18-35) from a Polish top-league club volunteered to participate. Inclusion criteria included active professional status, regular training participation, and no use of vitamin D or calcium supplements in the previous 3 months. Exclusion criteria included musculoskeletal injuries, metabolic disorders, or refusal to sign informed consent.
Measurements
Blood samples were collected at three time points:
T3: baseline (before supplementation),
T4: 48 hours post-supplementation (pre-match),
T5: immediately after the intra-squad game.
Serum concentrations of 25-(OH)D₃, 24,25-(OH)₂D₃, and 3-epi-25-(OH)D₃ were determined using LC-MS/MS. Additional biochemical variables (hemoglobin, glucose, testosterone, cortisol, ferritin, calcium, CK) were analyzed to monitor physiological status.
Outcomes
Primary Outcome: Changes in serum 25-(OH)D₃ concentrations after supplementation and exercise.
Secondary Outcomes: Changes in 24,25-(OH)₂D₃ and 3-epi-25-(OH)D₃ levels, metabolite ratios.
Ethics
The study was approved by the Ethics Committee of the Wroclaw University of Health and Sport Sciences (Resolution No. 1/2024, March 1, 2024). All participants signed written informed consent.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Keywords
Explore important study keywords that can help with search, categorization, and topic discovery.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
RANDOMIZED
PARALLEL
BASIC_SCIENCE
SINGLE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Supplementation Group (SGP)
Participants in this group received a single oral dose of 500,000 IU of vitamin D₃ (Vigantol Oil, P\&G Health, Germany) 48 hours before the intra-squad football match (ISG). Blood samples were collected before supplementation and both before and after the ISG to evaluate changes in vitamin D metabolites.
Vitamin D₃
A single oral dose of 500,000 IU vitamin D₃ (Vigantol Oil, P\&G Health, Germany) was administered 48 hours before the intra-squad football match to assess its acute effects on vitamin D metabolite concentrations.
Placebo Group (PGP)
Participants in this group received a single oral dose of placebo oil identical in color and consistency to the vitamin D₃ solution. Blood samples were collected at the same time points as in the supplementation group to assess vitamin D metabolite changes.
Placebo
A single oral dose of vegetable oil matching the vitamin D₃ solution in color and consistency was administered 48 hours before the intra-squad football match.
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Vitamin D₃
A single oral dose of 500,000 IU vitamin D₃ (Vigantol Oil, P\&G Health, Germany) was administered 48 hours before the intra-squad football match to assess its acute effects on vitamin D metabolite concentrations.
Placebo
A single oral dose of vegetable oil matching the vitamin D₃ solution in color and consistency was administered 48 hours before the intra-squad football match.
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
2. Actively training and competing in the Polish first football league
3. No vitamin D or calcium supplementation during the previous 3 months
4. No injuries or illnesses affecting participation
Exclusion Criteria
2. Chronic metabolic, endocrine, or renal disorders
3. Use of vitamin D or calcium supplements
4. Refusal or inability to sign informed consent
18 Years
35 Years
MALE
Yes
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Wroclaw University of Health and Sport Sciences
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Anna Książek
Associate Professor
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Anna Książek, PhD Eng.; Associate Professor
Role: PRINCIPAL_INVESTIGATOR
Department of Biological Principles of Physical Activity ; Wroclaw University of Health and Sport Sciences
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Wroclaw University of Health and Sport Sciences
Wroclaw, Dolnyśląsk, Poland
Countries
Review the countries where the study has at least one active or historical site.
References
Explore related publications, articles, or registry entries linked to this study.
Mieszkowski J, Stankiewicz B, Kochanowicz A, Niespodzinski B, Kowalik T, Zmijewski M, Kowalski K, Rola R, Bienkowski T, Antosiewicz J. Ultra-Marathon-Induced Increase in Serum Levels of Vitamin D Metabolites: A Double-Blind Randomized Controlled Trial. Nutrients. 2020 Nov 25;12(12):3629. doi: 10.3390/nu12123629.
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
AWF-VitD-Football-2024
Identifier Type: -
Identifier Source: org_study_id