PTH and osteoporosis: Patients with ESRD usually have osteoporosis and exhibit several metabolic and hormonal abnormalities, including decreased renal synthesis of 1,25(OH)2D3, hyperphosphatemia, hypocalcemia, increased secretion of PTH, chronic metabolic acidosis, and, more recently, 25(OH) vitamin D deficiency, which may affect bone growth and remodeling processes [23].