This book provides a comprehensive overview of functional foods, dietary supplements, and nutraceuticals, focusing on their role in maintaining health and preventing a range of diseases. It discusses the latest scientific findings on their efficacy, mechanisms of action, and potential benefits in various aspects of public health, including maternal and child nutrition, aging, and community-level nutrition education. The chapters offer insights into the bioactive components of these substances, their therapeutic effects, and how processing, storage, and environmental factors can influence their potency. Special attention is given to topics such as food adulteration, regulatory frameworks, good manufacturing practices (GMP), and pharmacopoeial standards for supplements and nutraceuticals. In addition, the book highlights emerging research areas, such as the benefits of isothiocyanates from plants, the role of vitamin B complex in supporting healthy pregnancy, and the use of functional foods in managing liver disorders and chronic diseases. Each chapter is supported by current data and provides an in-depth look at the molecular and clinical implications of these nutritional interventions. Further, pictorial descriptions in the form of tables, figures, flowcharts, etc. provide a vivid clarification of the concerned areas. Intended for students, academics, researchers, dietitians, and health professionals, this volume serves as a valuable resource for understanding the evolving landscape of functional nutrition and its applications in modern healthcare.