The correct answer is Calcium. Explanation & Key Takeaways: Calcium • Calcium builds strong bones and teeth and helps in muscle contraction, blood clotting, nerve transmission, and cell signalling and It also regulates metabolism. • The deficiency of calcium makes bone fragile and easy to fracture. Milk and dairy products, cashews, dates, broccoli, parsley, and greens are good sources of dietary calcium. Related Concepts: Iodine • It is the mineral used to produce thyroid hormones. It is necessary for the body’s metabolism and physical and mental development. Phosphorus deficiency leads to impaired growth in children and metabolic disorders such as goitre and mental problems and affects menstrual health and pregnancy-related issues. Iodized table salt is the main source and is easily available. Zinc • This mineral aids in cell division, immunity, and wound healing. Low zinc levels impair the immune system. Oysters, red meat, poultry, beans, nuts, and whole grains provide major quantities of zinc. Sodium • Sodium helps in muscle contraction, conducts nerve impulses, and controls the fluid balance in the body. • The primary source of dietary sodium is table salt. Potassium • Potassium plays a crucial role in maintaining fluid balance, muscle contraction, and nerve impulse conduction. It supports brain health and reduces the risk of stroke. Low potassium causes irregular heartbeats, edema (swelling), brain damage, etc. Bananas, sweet potatoes, avocados, beets, and dates are rich sources of potassium. Chloride • Chloride in association with sodium maintains the normal fluid balance in the body. It is used in the formation of hydrochloric acid (stomach acid) for digestion and to sustain electrical neutrality in the body. Table salt, tomatoes, celery, and lettuce are rich sources of chloride.