Calcium deficiency may not produce immediate symptoms because the body keeps blood calcium stable by drawing from bone stores. If this compensation persists, bone mineral density can decline and the risk of osteopenia/osteoporosis increases. Possible symptoms include muscle cramps, tingling or numbness (often around lips/hands), brittle nails, dental sensitivity, fatigue, and rarely rhythm disturbances. These signs are not specific—vitamin D deficiency, low magnesium, or thyroid/parathyroid issues can contribute. Clinically, “low intake” is not the same as “low blood calcium.” Many people have normal serum calcium while bone stores are being depleted. Therefore, management focuses on improving dietary intake, assessing vitamin D status, and using a clinician-guided plan when supplementation is needed. Severe spasms, confusion, or palpitations warrant urgent evaluation.