The first 1,000 days—from conception to a child’s second birthday—represent a critical window for growth, development, and long-term health. Nutrition during this period lays the foundation for growth, cognitive development, immune function, and chronic disease risk. Research in this area helps inform global strategies to improve maternal and child health outcomes. Dr. Kyly Whitfield is an Associate Professor in the Department of Applied Human Nutrition at Mount Saint Vincent University and is passionate about international nutrition, with interests in identifying and combating micronutrient deficiencies during ‘the first thousand days’ window. Her research focuses on maternal thiamin deficiency and infantile beriberi, mainly in rural Cambodia, an area where thiamin-related infant mortality remains a major public health issue. Alongside a few fellow CNS members, Kyly also co-edited a book titled ’The biology of the first 1,000 days’ which is a cross-disciplinary deep dive that explores the biological underpinnings of this critical developmental window. In this episode, Dr. Whitfield discusses global micronutrient deficiencies in the first 1000 days with a focus on thiamin.