Seasonal variability of the vitamin D effect on physical fitness in adolescents

• Published in: Scientific reports Vol. 11; no. 1; pp. 182 - 10
• Main Authors: Milani, Gregorio P., Simonetti, Giacomo D., Edefonti, Valeria, Lava, Sebastiano A. G., Agostoni, Carlo, Curti, Maurus, Stettbacher, Andreas, Bianchetti, Mario G., Muggli, Franco
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.01.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 692/700/1720; 692/700/1720/3187; Adolescents; Autumn; Body fat; Hemoglobin; Humanities and Social Sciences; multidisciplinary; Physical activity; Physical fitness; Regression analysis; Science; Science (multidisciplinary); Seasonal variations; Vitamin D
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-80511-x

Studies investigating the relationship between vitamin D and physical fitness in youth have provided inconsistent findings. Recent evidence indicates that the expression of receptors and vitamin D-modulated genes in young subjects has a seasonal profile. Therefore, we investigated the role of vitamin D on physical fitness across seasons in a total of 977 male adolescents. Anthropometrics, lifestyle, dietary habits, biochemical profiles and physical fitness were studied. Multiple linear regression models, including pairwise interaction terms involving total 25-OH-vitamin D, were fitted. The interacting effect of season and total 25-OH-vitamin D had a significant influence on physical fitness performance (spring and total 25-OH-vitamin D: ß 0.19, SE 0.07, p = 0.007; summer and total 25-OH-vitamin D: ß 0.10, SE 0.06, p = 0.11; autumn and total 25-OH-vitamin D: ß 0.18, SE 0.07, p = 0.01), whereas the main effect of total 25-OH-vitamin D alone was not significant (p = 0.30). Body fat percentage, recreational physical activity level, time spent per day gaming/TV-watching, smoking, and hemoglobin levels were also related to the physical fitness performance score. Future studies should further explore the role of seasonal-dependent effects of vitamin D on health.