No Association between Serum Vitamin D and Physical Fitness in Trained Youth Soccer Athletes

Abstract

Vitamin D is known to affect bone health and muscle function. Insufficient vitamin D (25(OH)D) status may negatively affect adolescent physical performance levels. PURPOSE: To examine the cross-sectional association between 25(OH)D status and several markers of physical performance in youth club soccer athletes. METHODS: 42 adolescent, male and female club soccer players age 14-18 were recruited during the winter season. 25(OH)D status, measured in January, was assessed from a capillary blood sample analyzed using liquid chromatography-tandem mass spectrometry. Physical performance was evaluated using a variety of agility, muscular strength, and cardiorespiratory fitness tests. Participants were classified as 25(OH)D Deficient (<50 nmol/L), Insufficient (50-75 nmol/L), or Sufficient (>75 nmol/L) and a relationship between physical performance and 25(OH)D classification was determined using a one-way ANOVA. RESULTS: Mean 25(OH)D status was 67.0 ± 16.7 nmol/L. 19% (8/42) of the participants were vitamin D deficient, 55% (23/42) were vitamin D insufficient, and 26% (11/42) were vitamin D sufficient. There were no associations found between 25(OH)D status and the variety of agility, muscular strength, and cardiorespiratory fitness tests (p > 0.05). CONCLUSIONS: This investigation demonstrates there are no associations between 25(OH)D status and physical performance in adolescent soccer players. Our participants were competitive adolescent athletes with none being severely deficient which may mask associations in this population group.