engleski

Vitamin D status among youth soccer players; association with chronological age, maturity status, jumping and sprinting performance

Purpose: Vitamin D is known to have a significant role in numerous body-system processes. Specifically, it has an impact on muscle functioning and, therefore sports performance. Children and adolescents have increased need for vitamin D because of its importance in growth and development, and it is evident that they are more susceptible to have vitamin D deficiency. Consequently, vitamin D status is particularly important issue in youth competitive sport. The aim of this study was to determine the prevalence of vitamin D deficiency/insufficiency (measured as 25(OH)D concentration), and the possible associations between vitamin D, with age, maturity status, sprinting- and jumping- performance among youth soccer players. Methods: The sample of participants in this research comprised 62 youth soccer players (age: 15.7±2.2 years). They were divided into two categories according to 25(OH)D levels measured at the end of the winter season: group with inadequate levels of 25(OH)D (vitamin D deficiency/insufficiency [<75 nmol/L]), and group with adequate levels of 25(OH)D (vitamin D sufficiency [>75 nmol/L]). Biological maturity status (maturity offset) was calculated from participants age and height by the following equation: Maturity offset = -7.999994 + (0.0036124 x (age(yrs.) x height(cm)). Performance variables were 10 meters sprint test (S10m) and countermovement jump test (CMJ). Results: Results showed relatively good 25(OH)D concentrations (78.32±23.39 nmol/L), with prevalence of deficiency (<50nmol/L) in 8.06%, and insufficiency (50-75 nmol/L) in 46.77% athletes. Significant correlations were evidenced between the CMJ and 25(OH)D level (R=0.27, p<0.05), but chronological age was also correlated with CMJ (R=0.64, p<0.05). Further, higher chronological age was found in participants with sufficient vitamin D levels (15.1±2.4 vs. 16.4±1.6 years ; t-test=2.43, p<0.05). However, no significant association was evidenced between vitamin D and maturity status. Conclusion: Vitamin D groups significantly differed by chronological age but not by maturity status, which collectively with correlation between CMJ and vitamin D status indicates that both vitamin D status and performance in youth soccer players is actually influenced by chronological age. Meanwhile, biological age doesn’t have a significant physiological influence on vitamin D concentration, while some external factors (i.e. time spent outdoors, parental control, sunscreen usage), should be considered important.

Vitamin D ; age ; maturity ; jumping ; sprinting ; soccer

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