title: Association of plasma 25-hydroxyvitamin D with physical performance in physically active children.
abstract: Vitamin D is thought to regulate skeletal muscle function and boost physical performance. The aim of this study was to assess the relationship between vitamin D and physical performance in physically active children. This cross-sectional study included 125 children who practice football as a leisure activity. Plasma 25-hydroxyvitamin D (25-OHD) was assessed using a chemiluminescence immunoassay method. Vitamin D inadequacy was defined as 25-OHD < 20 ng/mL. Physical performance testing included measurements of muscle strength (maximal isometric contraction), jumping ability (vertical jump, standing broad jump, triple hop test), linear sprint (10 m and 20 m), and agility (9 × 4-m shuttle run). Plasma 25-OHD concentrations were positively correlated with muscle strength (r = 0.539; p < 0.001), vertical jump (r = 0.528; p < 0.001), and standing broad jump (r = 0.492; p < 0.001) but inversely correlated with sprint performance (r = -0.539; p < 0.001). In multivariate analysis models, plasma 25-OHD concentrations were associated with each physical performance parameter independently of age, maturity status, body mass index, fat mass, and protein and calcium intakes. In conclusion, a low plasma 25-OHD level was associated with decreased muscle strength, agility, and jumping and sprinting abilities in physically active children. Vitamin D inadequacy may limit exercise performance. Further research should verify whether correction of vitamin D deficiency enhances physical performance.
authors.affiliation: a Rabta Hospital, Laboratory of Biochemistry, LR99ES11, 1007 Tunis, Tunisia.|b National Center of Medicine and Sciences in Sports, Tunisian Research Laboratory "Sport Performance Optimization", 2010 Tunis, Tunisia.|c University Tunis El Manar, Faculty of Medicine of Tunis, 1007 Tunis, Tunisia.
authors.forename: Ikram
authors.initials: I
authors.lastname: Bezrati
authors.affiliation: b National Center of Medicine and Sciences in Sports, Tunisian Research Laboratory "Sport Performance Optimization", 2010 Tunis, Tunisia.
authors.forename: Raouf
authors.initials: R
authors.lastname: Hammami
authors.affiliation: a Rabta Hospital, Laboratory of Biochemistry, LR99ES11, 1007 Tunis, Tunisia.
authors.forename: Mohamed Kacem
authors.initials: MK
authors.lastname: Ben Fradj
authors.affiliation: d University of Naples, 80138 Naples, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Martone
authors.affiliation: b National Center of Medicine and Sciences in Sports, Tunisian Research Laboratory "Sport Performance Optimization", 2010 Tunis, Tunisia.|e eCampus University, 22060 Novedrate, Italy.|f University of Split, Faculty of Kinesiology, 21000 Split, Croatia.
authors.forename: Johnny
authors.initials: J
authors.lastname: Padulo
authors.affiliation: a Rabta Hospital, Laboratory of Biochemistry, LR99ES11, 1007 Tunis, Tunisia.|c University Tunis El Manar, Faculty of Medicine of Tunis, 1007 Tunis, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Feki
authors.affiliation: b National Center of Medicine and Sciences in Sports, Tunisian Research Laboratory "Sport Performance Optimization", 2010 Tunis, Tunisia.
authors.forename: Anis
authors.initials: A
authors.lastname: Chaouachi
authors.affiliation: a Rabta Hospital, Laboratory of Biochemistry, LR99ES11, 1007 Tunis, Tunisia.
authors.forename: Naziha
authors.initials: N
authors.lastname: Kaabachi
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000293:Adolescent; D000294:Adolescent Behavior; D054874:Athletic Performance; D002112:Calcifediol / Q000097:blood*; D002648:Child; D002652:Child Behavior; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D000070497:Healthy Lifestyle; D006801:Humans; D008297:Male; D009043:Motor Activity; D053580:Muscle Strength; D018908:Muscle Weakness / Q000209:etiology*; D010809:Physical Fitness; D015995:Prevalence; D012916:Soccer; D000072264:Sports and Recreational Facilities; D014142:Track and Field; D014416:Tunisia / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*
chemical_list: D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol
keywords: children; enfants; force musculaire; muscle strength; performance physique; physical performance; vitamin D; vitamine D