Calcium deficiency can lead to several warning signs that affect various aspects of health. These include tooth decay due to weakened enamel, frequent fractures from brittle bones, and fatigue from reduced energy levels. Other symptoms may include muscle cramps, brittle nails, dry skin, numbness or tingling sensations, and even mood changes. In the long term, calcium deficiency can contribute to conditions like osteoporosis, irregular heartbeats, and stunted growth in children. It's essential to maintain adequate calcium intake to support bone, dental, and overall health.