Calcium is an essential mineral for building strong bones and teeth, and for the proper functioning of the heart and muscles. A deficiency in calcium increases the risk of developing osteoporosis and calcium deficiency disease. To prevent calcium deficiency, include calcium-rich foods like salmon, broccoli, and figs in your diet. The recommended daily allowances for calcium are the same for both children and teenagers, but differ for adults. Women need to increase their calcium intake earlier in life, especially around menopause. Calcium deficiency can be caused by various factors such as malnutrition and malabsorption. Early-stage calcium deficiency might not show symptoms, but long-term deficiency can lead to serious issues like brittle nails, slow hair growth, and thin skin. Severe deficiency can cause seizures and neurological symptoms. Doctors diagnose calcium deficiency through blood tests. Treatment typically involves dietary adjustments and calcium supplements, with severe cases requiring regular calcium injections. The best way to prevent calcium deficiency is to consume adequate calcium daily, and ensure sufficient vitamin D intake to aid calcium absorption. Choose low-fat or fat-free dairy products, include calcium and vitamin D-rich foods like milk, yogurt, fish, and mushrooms in your diet, and get regular sun exposure to maintain healthy calcium and vitamin D levels.