Dietary Supplement Use from Infancy to Adolescence in Croatia: Prevalence, Types and Associated Factors

Background/Objectives: Although the use of dietary supplements is increasing worldwide among the pediatric population, comprehensive national data on consumption patterns in Croatia remain limited. The aim of this study was to assess the prevalence and types of dietary supplement use in a national pediatric sample in Croatia, as well as the intake of active compounds and the factors influencing supplement use. Methods: This cross-sectional study analyzed data from 2078 participants from two Croatian national food consumption studies (NIPNAD 2017–2021 and NIPNOD 2018–2023), both of which followed standardized EU Menu methodology protocols. Results: The unweighted overall prevalence of dietary supplement use based on dietary records and 24 h recalls was 37.5%, highest among infants (74.5%) and declining significantly by adolescence (13.2%). Vitamin-only formulations, predominantly vitamin D, were most common in infants, whereas mixed formulations combining herbs with vitamins and minerals were most prevalent in children. Median daily vitamin and mineral intakes from dietary supplements were generally below the tolerable upper intake levels proposed by the European Food Safety Authority, except for some occasional acute exceedances in the infant group, which do not reflect habitual intake or indicate a potential risk. Several age-specific determinants of dietary supplement use emerged, including region of residence, weight status, energy intake, physical activity level, type of diet, and presence of chronic disease. Conclusions: The results of this study highlight age-specific differences in dietary supplement use driven by diverse sociodemographic and lifestyle factors. To accurately assess the risks associated with dietary supplement use, future studies must consider nutrient intake from both foods and supplements. These findings highlight the need for targeted public health programs to monitor dietary supplement use and related behaviors and to promote safe supplementation in pediatric populations.