Calcium is the primary mineral responsible for the structural integrity of bones and teeth. It combines with phosphate to form hydroxyapatite crystals, which provide rigidity and strength to the bone matrix. Adequate calcium levels are critical for maintaining bone density and preventing conditions like osteoporosis. In teeth, calcium contributes to enamel hardness, which is essential for resisting mechanical forces and decay. Deficiency in calcium directly impacts bone remodeling and repair, making it a vital element in skeletal health.

Reference: Gray's Anatomy, Susan Standring, 42nd Edition.