This chapter presents an analysis of the role of vitamins, minerals, and bioactive compounds in human nutrition, emphasizing their importance in maintaining health and preventing diseases. Although these micronutrients are required in small quantities, they play essential roles in physiological processes, such as energy metabolism, tissue synthesis, immune function, and protection against oxidative stress. Vitamins are classified into two major groups: fat-soluble (A, D, E, and K) and water-soluble (B-complex and vitamin C). Each group has unique characteristics in terms of dietary sources, absorption mechanisms, metabolism, and impact on health. Vitamin A, for example, is essential for ocular health, immune function, and epithelial integrity. Deficiency of this vitamin can lead to night blindness and weakened immune function, while its excess can result in toxicity, with symptoms such as nausea, vomiting, and liver damage. B-complex vitamins are crucial for cellular metabolism and energy production, acting as coenzymes in various enzymatic reactions. Deficiency of these vitamins can lead to anemia and severe neurological disorders. Vitamin D is vital for calcium absorption and bone health, while vitamin E possesses antioxidant properties, protecting cells from oxidative damage. Vitamin K is important for blood clotting and bone health. In addition to vitamins, this chapter explores the importance of minerals, such as calcium, iron, magnesium, zinc, sodium, and potassium. Calcium is the most abundant mineral in the human body and is essential for the formation and maintenance of bones and teeth, as well as participating in blood clotting and nerve signal transmission. Its deficiency can lead to osteoporosis and rickets, while excess calcium can cause kidney stones and interfere with the absorption of other minerals. Iron is vital for oxygen transport in the blood and energy metabolism, and iron deficiency is one of the most common nutritional deficiencies globally, leading to iron deficiency anemia. This chapter also highlights the role of bioactive compounds found in foods, such as carotenoids, polyphenols, and flavonoids. Although not considered essential nutrients, these compounds have antioxidant, anti-inflammatory, and chemopreventive properties, contributing to the protection against chronic diseases such as cancer, cardiovascular diseases, and neurodegenerative disorders. The bioavailability and impact of these compounds on health can vary depending on factors, such as the food matrix, interactions with other nutrients, and the individual’s physiological state.