The effect of vitamin D3 supplementation on vitamin D status and associated health outcomes in children: a randomised controlled trial.

Vitamin D insufficiency is prevalent in UK/Irish children and supplementation in the form of an oral spray is effective in achieving/maintaining an adequate status in most children. Further research is warranted to elucidate mechanisms underpinning non-response to supplementation and to further investigate the potential beneficial effects of supplementation on cognitive function. This trial was registered with ClinicalTrials.gov (NCT05018988: https://clinicaltrials.gov/study/NCT05018988).