Use of vitamin D supplements during infancy in an international feeding trial.

Objective: To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial. Design: Longitudinal study. Setting: Information about vitamin D supplementation was collected through a validated FFQ at the age of 2 weeks and monthly between the ages of 1 month and 6 months. Subjects: Infants (n 2159) with a biological family member affected by type 1 diabetes and with increased human leucocyte antigen-conferred susceptibility to type 1 diabetes from twelve European countries, the USA, Canada and Australia. Results: Daily use of vitamin D supplements was common during the first 6 months of life in Northern and Central Europe (. 80% of the infants), with somewhat lower rates observed in Southern Europe (. 60 %). In Canada, vitamin D supplementation was more common among exclusively breast-fed than other infants (e. g. 71% v. 44% at 6 months of age). Less than 2% of infants in the USA and Australia received any vitamin D supplementation. Higher gestational age, older maternal age and longer maternal education were study-wide associated with greater use of vitamin D supplements. Conclusions: Most of the infants received vitamin D supplements during the first 6 months of life in the European countries, whereas in Canada only half and in the USA and Australia very few were given supplementation.