Predictors of Differences in Vitamin D Levels in Children and Adolescents and Their Relation to Endurance Performance

Aims: The present study investigated whether sociodemographic
factorsand physical activity (PA) are associated with differences
in serum25-hydroxyvitamin D [25(OH)D] levels and whether these
differences areassociated with varying levels of endurance
performance and body massindex (BMI) in children and adolescents.
Subjects and Methods: Pathanalyses were based on data of a
nationwide, cross-sectional GermanHealth Interview and Examination
Survey for Children (KiGGS; 2003 until2006) for 25(OH)D and the
embedded ‘motor function module’ for PA andendurance performance.
The data were collected from 3,437 children andadolescents aged
6-17 years clustered in three age groups: 6-10, 11-13and 14-17
years. Results: PA is affected by socioeconomic status
and(non-)immigration background, 25(OH)D is only affected
by(non-)immigration background and only in childhood. PA and
25(OH)D werenot associated in those aged 11-13 years. In
adolescence, lower 25(OH)Dlevels are associated with lower
endurance performance and a higher BMI.Conclusions: Our results did
not reveal a universally significant effectof sociodemographic
factors on 25(OH)D. The association between 25(OH)Dand endurance
performance might reflect the effects of 25(OH)D on musclefunction.
Predictors of 25(OH)D status other than sunlight exposure andits
health effects in the pediatric age group should be
exploredfurther.