Calcium and sodium are essential minerals required for maintaining diverse physiological processes that support growth, health, and metabolic balance in the human body. Their significance in food and nutrition lies not only in their biological functions but also in the understanding of their dietary sources, absorption mechanisms, and the consequences of deficiency or excess. Calcium is primarily known for its role in bone development and maintenance, while sodium is crucial for fluid balance and nerve transmission. Both minerals interact closely with other nutrients and systems, making them important subjects in the study of Fundamentals of Food and Nutrition. Calcium is the most abundant mineral in the human body, forming a major structural component of bones and teeth. Approximately 99 percent of the body’s calcium is stored in the skeletal system, while the remaining one percent exists in blood and soft tissues where it plays vital metabolic roles. Dietary sources of calcium are wide-ranging, but the richness of different foods varies remarkably. Milk and milk products, including curd, cheese, paneer, buttermilk, and yogurt, are considered the most bioavailable sources because they provide calcium along with vitamin D and lactose, which enhance its absorption. Among plant sources, green leafy vegetables such as spinach, amaranth, methi, and broccoli contain significant amounts of calcium, although bioavailability may be reduced in some due to oxalates and phytates. Cereals like ragi (finger millet) offer substantial calcium content and form an important