The effects of cholecalciferol supplementation on the inflammatory markers and muscle damage indices of soccer players after a simulated soccer match

Soccer-induced muscle damage and inflammation lead to a reduction in athletic
performance. The purpose of this study was to determine whether supplementation with
cholecalciferol would reduce inflammation and muscle damage in soccer players after a simulated
soccer match.
Methods: Twenty-two soccer players (median age: 27 years, inter-quartile range: 5 years) were
divided randomly into two groups, as follows: a cholecalciferol group (n = 11) and a placebo group (n
= 11). Cholecalciferol supplements (50,000 IU/week) or placebos were administered to the groups by
an independent coworker. After 8 weeks, the athletes participated in a simulated soccer match, and
perceived exertion and heart rates were measured during the trial. Blood samples were obtained presupplementation, post-supplementation, immediately after, and 2- and 24-h post-exercise for
measurement of lactate dehydrogenase (LDH), creatine phosphokinase (CPK), C-reactive protein
(CRP), and interleukin 6 (IL-6).
Results: The intervention group demonstrated a significant increase in serum 25(OH)D levels (53.93,
10.68 ng/mL, p < 0.0001), which is the best indicator of vitamin D levels in the body, with no change
in the circulating markers of muscle damage and CRP (p ˃ 0.05) but showed increased IL-6 (P =
0.034). In addition, the ratings of perceived exertion and heart rates were not altered by vitamin D
versus placebo ingestion (p = 0.155 vs. p = 0.261; p = 0.600 vs. p = 0.983).
Conclusion: The study showed that 50,000 IU/week of cholecalciferol supplementation for eight
weeks, increased the 25(OH)D levels, with no effect on muscle damage indices or CRP. However,
The IL-6 concentration was generally higher in the intervention group