Both belong to primary osteoporosis Postmenopausal osteoporosis is called osteoporosis type I. Postmenopausal women, around 50 years old, are mainly due to endocrine changes in the body, due to the decrease of estrogen, the effect of estrogen on bone metabolism is mainly to promote the secretion of calcitonin, indirectly inhibit the function of osteoclasts and reduce bone resorption. Age-related osteoporosis, also known as osteoporosis type II, has an age of onset around 70 years old and can also occur in elderly women, mainly due to the aging and decreasing function of tissues and organs: 1. Decline in the function of osteoblasts in the elderly, reducing bone formation; decreasing kidney function, decreasing the amount of 25(OH)D3 converted into 1,25(OH)D3 in the kidneys; affecting calcium absorption; 2. Decreasing function of mucosal epithelial cells in the small intestine The formation of calcium-binding protein is insufficient, or its activity is reduced, affecting the absorption of calcium in the intestine; 3, the synthesis of a variety of proteins is reduced, affecting the formation of bone matrix. 4, the reduction of androgens is also a factor.