➤ A component of bone and dental tissue: Ca₂(OH)PO₄ or CaCO₃ + Ca₃(РО₄)₂, and is responsible for the strength of bone tissue and teeth. It regulates the contraction of various muscle groups, including the heart, the functioning of the central nervous system, blood clotting processes, the activity of enzymes and hormones, the course of biochemical processes, the functioning of cell membranes and the immune system, and the balance of osmotic pressure. It is considered to be a potassium antagonist, promotes myocardial contraction.

➤ Hypercalcemia, which leads to hardening of bones, kidney stones, and heart attack.

➤ Causes abdominal cramps, pharyngeal reflex, loss of appetite, polydipsia, weakness, and weight loss.

➤ Hypocalcemia causes osteoporosis, muscle cramps and myalgia, tremors and numbness in the limbs, deterioration of nails and teeth, and heart rate disorders.

➤ Antidote: taking calcium supplements.

➤ CaCl₂ (Calcium chloride) - P-in. 100mg/ml

➤ C₁₂H₂₂CaO₁₄ (Calcium gluconate) - 1-3 g 2-3 p/d. 10% solution is used intravenously and intramuscularly, anti-allergic, anti-inflammatory, relieves convulsions.

➤ CaH₂ - 5-10% solution 2-3 times a day, increases blood clotting, anti-allergic, anti-inflammatory effect, diuretic effect.

➤ CaSO₄-2H₂O - gypsum, fixation of fractures.

➤ In dentistry: Calcium gluconate 10% solution - applications to increase the resistance of tooth tissues.

➤ Ca(OH)₂ - as an antimicrobial agent for the treatment of pulpitis (preferable to antibiotics).

➤ Measures to prevent and treat osteoporosis, regulate blood pressure, and ensure muscle tone and nerve impulse transmission.

➤ Consumption of eggshells, dairy products, and trine to prevent or treat diseases of the musculoskeletal system. .

➤ Causes gastrointestinal disorders and leads to ulcers.

➤ There is no specific antidote.

➤ In the first century AD, the physician Dioscorides called CaO "quicklime".

➤ "Fluff" - Ca(OH)₂ powder.

➤ "Milk of lime" - a mixture of Ca(OH)₂ + H₂O.

➤ "Arbolit" - a mixture of cement, CaCl₂, sawdust, H₂O, does not burn, does not rot, can be cut with a saw, and is used as a building material.

➤ Concrete is 2 thousand years old.

➤ In space, Ca⁺² is washed out of bones.