Calcium and phosphorus are the most important minerals of the bone with 1-2 kg of calcium and 1 kg of phosphorus stored in it. Metabolism of calcium and phosphorus are chiefly regulated by vitamin D and parathormone. Calcium supplements are used for replacement in deficiency states, in pregnant and lactating women, in postmenopausal osteoporosis and in rickets. Vitamin D is a fat soluble vitamin produced in the skin from 7-dehydrocholesterol under the influence of ultraviolet rays. It is used for the prophylaxis and treatment of vitamin D deficiency. Calcitonin is a peptide hormone secreted by the parafollicular C cells of the thyroid gland. It is used to control hypercalcemia and to increase bone mineral density. Drugs used in the disorders of bone include bisphosphonates, raloxifene and vitamin D. Bisphosphonates inhibit bone resorption and are therefore useful in post menopausal osteoporosis, hypercalcemia and in Paget’s disease.