To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial.

Longitudinal study.

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.

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.

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.

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.

We investigated behavioural and socio-economic factors associated with obesity and weight dissatisfaction among Finnish adolescents.

A total of 60252 Finnish adolescents aged 14 to 16 years filled in a questionnaire about their health, health behaviour and socio-economic background. Food choices were obtained by using a short food-frequency questionnaire. Obesity was defined as a weight at least 120% of the sex- and height-specific mean weight for subjects.

Of girls and boys, 54% and 66%, respectively, were satisfied with their weight. Among dissatisfied normal-weight adolescents, 81% of girls but only 48% of boys thought they were overweight. Of obese boys, 25% were satisfied with their weight. For both genders, obesity and weight dissatisfaction were associated with economic problems in the family. In girls, an association was also found with poor school performance, low educational level of parents and not having evening meals at home; and in boys, with physical inactivity and not eating school lunch. Smoking was more common among girls who were dissatisfied with their weight. Differences in food choices were small between different weight and weight satisfaction categories.

Having normal weight and being satisfied with that weight are favourable for an adolescent. Obesity and weight dissatisfaction are associated mostly with disadvantageous health behaviours and low socio-economic status. Health behaviour seems to be associated more with weight satisfaction than with actual weight.