High-Dose Vitamin D Supplementation and Exercise Effects on Vitamin D Metabolites in Professional Football Players

Summary

This randomized, single-blind, placebo-controlled pilot study investigated the effects of high-dose vitamin D₃ supplementation and football-specific physical exercise on vitamin D metabolite concentrations in professional male football players. The study aimed to evaluate the acute response of circulating vitamin D metabolites, including 25-(OH)D₃, 24,25-(OH)₂D₃, and 3-epi-25-(OH)D₃, following a single oral dose of 500,000 IU cholecalciferol combined with high-intensity intermittent exercise typical of competitive football.

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.

Conditions

• Vitamin D Deficiency (10 ng/mL to 30 ng/mL)
• Athletes
• Football Players
• Exercise Physiology

Interventions

DIETARY_SUPPLEMENT

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.

OTHER

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.

Sponsors & Collaborators

• Wroclaw University of Health and Sport Sciences

  lead OTHER

Principal Investigators

• Anna Książek, PhD Eng.; Associate Professor · Department of Biological Principles of Physical Activity ; Wroclaw University of Health and Sport Sciences

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-04-27

Primary Completion

2024-05-17

Completion

2024-06-24

Countries

• Poland

Study Locations