Physical activity but not sedentary time is associated with vitamin D status in adolescents: study of cardiovascular risk in adolescents (ERICA)

Background/objectives The association between active lifestyle components and vitamin D status in adolescents remains relatively unexplored. We aimed to investigate independent and joint associations of moderate-to-vigorous physical activity (MVPA) and screen time with serum 25-hydroxyvitamin D [25(OH)D] concentrations in adolescents. Methods This multicenter cross-sectional study involved 1152 Brazilian adolescents (age 12-17 years). Serum 25(OH)D was measured in a single laboratory and categorized as <= 20, 21-29, or >= 30 ng/mL. Demographic and lifestyle characteristics were assessed by self-reports. Ordered logistic regression was used to investigate potential associations of being physically active (MVPA >= 300 min/week) and excessive screen time (>2 h/day) with serum 25(OH)D concentrations. Results The prevalence of higher serum 25(OH)D concentrations (>= 30 ng/mL) was 36.4%. In adjusted models, being physically active was associated with higher serum 25(OH)D concentrations only in boys [proportional odds ratio (POR) = 2.04, 95% CI 1.42-2.93], while excessive screen time was not associated with serum 25(OH)D. Adolescents who were physically active and limited their screen time had higher odds of a higher serum 25(OH)D concentration, but the association was significant only for boys (POR = 2.11, 95% CI 1.19-3.74). Conclusions MVPA may play an important role in increasing serum 25(OH)D concentrations in adolescence, especially for boys, regardless of screen time.