This review offers a comprehensive exploration of the critical role nutrition plays in the first 1000 days of life, from conception through the second year. This period is highlighted as a uniquely sensitive phase of development, where the brain, gut and sleep systems undergo rapid and coordinated maturation. The review discusses the role that key nutrients play in the development of these systems — including omega-3 fatty acids, choline, folate and vitamin D.
Nutrition is highlighted as a key modifiable factor shaping this gut–brain–sleep triad. Evidence suggests that key nutrients — such as omega-3 fatty acids, choline, folate and vitamin D — support neurodevelopment, gut microbiome maturation and sleep regulation.
This review also evaluates clinical trials exploring the long-term effects of nutritional supplementation during this development period. Given widespread suboptimal intakes and limitations in current biomarkers, the authors highlight the need for improved tools to detect early nutrient deficiencies and for well-designed trials to better inform evidence-based nutritional guidance during this critical window of life.
