Linking vitamin D status, executive functioning and self-perceived mental health in adolescents through multivariate analysis: A randomized double-blind placebo control trial
The aim of the present randomizeddouble-blindplacebocontroltrial was to investigate if vitaminD supplementation had an effect on vitamin D status, executivefunctioning and self-perceivedmentalhealth in a group of Norwegian adolescents during winter time. Fifty adolescents were randomly assigned into an intervention group (vitaminD pearls) or a control group (placebo pearls).
Before (pre-test in December/January) and after (post-test in April/May) the intervention period the participants were exposed to a test procedure, consisting of blood draw, completion of cognitive tests (Tower of Hanoi and Tower of London), and the Youth Self-report version of the Child Behavior Checklist. Multivariate data analysis showed that participants with low vitaminDstatus scored worse on the Tower of London tests and the more difficult sub-tasks on the Tower of Hanoi tests. They also had a tendency to report higher frequency of externalizing behavior problems and attention deficit. At pre-test, the overall mean vitaminDstatus measured as 25-hydroxy vitaminD was 42 nmol/L, defining deficiency (Intervention group = 44 nmol/L, Control group = 39 nmol/L).
However, vitaminD supplementation caused a significant increase in vitamin D status resulting in a sufficient level in the Intervention group at post-test (mean 62 nmol/L). The results also revealed that the intervention group improved their performance on the most demanding sub-tasks on the ToH. Overall, the study indicates that vitaminDstatus in adolescents may be important for both executivefunctioning and mentalhealth.