CONSUMER TRENDS, INGREDIENT INNOVATION, AND THE EVOLVING SCIENCE BEHIND CHILDREN'S IMMUNE- HEALTH NUTRACEUTICALS From "Immune Boosting" to Evidence-Based Paediatric Immune Resilience

Children's immune health has evolved from a predominantly seasonal supplement category into a major field of paediatric nutritional innovation. Parents increasingly seek products positioned around immunity, gut health, cognitive development and broader resilience while simultaneously demanding convenient formats, low or no added sugar, natural or recognisable ingredients, clean-label positioning, transparency and credible scientific substantiation. Contemporary market data illustrate this transformation. In the United States, children's supplement sales across major measured channels reached approximately USD 1.29 billion between July 2025 and July 2026, with gummies accounting for approximately USD 581 million. Immune/cold-and-flu positioning represented approximately USD 170 million over the same period. International consumer research likewise places immune health among the leading priorities of parents of children aged 3-12 years. These commercial observations, however, constitute evidence of consumer demand rather than evidence of clinical efficacy. The scientific landscape is substantially more complex. 'Immune support' is frequently communicated as if it were synonymous with infection prevention, yet immune competence is a multidimensional developmental state involving epithelial barrier function, innate and adaptive immune responses, immune tolerance, inflammatory regulation, immunological memory and bidirectional interactions with the microbiota. Deficiencies of micronutrients such as vitamins A and D, zinc, iron and selenium can compromise host defence, but correcting deficiency must be distinguished from supplementing already replete children in an attempt to obtain supra-physiological protection. Contemporary evidence therefore supports a shift from the poorly defined concept of 'immune boosting' toward the more biologically coherent construct of paediatric immune resilience. At the same time, ingredient research is expanding beyond conventional vitamin-mineral combinations toward strain- specific probiotics, prebiotics and synbiotics, postbiotics, human-identical milk oligosaccharides (HiMOs), lactoferrin, milk fat globule membrane (MFGM), beta-glucans and other biologically active systems. These platforms offer compelling mechanistic rationales but markedly heterogeneous levels of clinical validation. Recent systematic reviews and randomized trials demonstrate why entire ingredient classes cannot legitimately inherit the evidence generated for individual strains, structures, preparations or formulations. This structured critical review examines the convergence of paediatric immune development, consumer behaviour, nutritional science, microbiome research, ingredient innovation, formulation technology, safety assessment, clinical-trial methodology and regulatory science. It proposes two integrated conceptual frameworks - the Paediatric Immune Resilience Model and the Seven-Layer Evidence Architecture for Paediatric Immune Products - and argues that the next generation of clinically credible products will be distinguished not by the length of their ingredient lists but by biological coherence, age-appropriate dosing, analytical characterisation, formulation stability, clinically meaningful endpoints, transparent evidence hierarchies and regulatory-compatible communication.