As you age, the 'silent epidemic' of osteoporosis may be approaching you. Overweight, extreme thinness, excessive sun protection, lack of vitamin D, and superstitions about losing weight in old age are all affecting bone health. On the occasion of the 30th World Osteoporosis Day, the China Association for Health Promotion and Education and the China Health Promotion Foundation jointly held the "2025 Healthy Skeleton Science Popularization and Communication Conference", where attending experts worked together to promote public bone health. Professor Xia Weibo, director of the endocrinology department at Peking Union Medical College Hospital, explained that scientific weight management is closely related to bone health. Both low body weight and obesity increase the risk of fractures, with individuals with abdominal obesity and larger waist circumference having a higher risk of fractures. At the same time, it is recommended that the public reduce body fat, especially visceral fat, while maintaining and increasing muscle mass through exercise to promote bone health and overall health. At the same time, excessive weight loss also affects bone health. Professor Hou Jianming, chief physician of the Endocrinology Department of Fuzhou University Affiliated Provincial Hospital, reminds that excessive weight loss in the short term can lead to nutritional deficiencies, insufficient intake of calcium, vitamin D, and protein, endocrine disorders, decreased hormone levels, imbalanced bone metabolism, and weakened mechanical stimulation. Especially in young women, excessive weight loss may lead to endocrine and metabolic disorders, decreased estrogen levels, overactive osteoclasts, decreased bone quality and strength, and increased risk of fractures. The age of forty or fifty is the turning point of bone mass decline. Professor Xu Youjia, chief physician of the Orthopedics Department of the Second Affiliated Hospital of Soochow University, said that normal human bones are very hard, but after osteoporosis, brittle fractures may occur when falling from a standing height, especially in the vertebral body, hip, proximal humerus (shoulder), and distal radius (wrist). Professor Xu Youjia reminds the public that there is a "turning point" in the decline of bone mass from the age of 40-50, and the turning point of bone mass decline is the starting point for us to pay attention to increasing bone mass and preventing osteoporosis. Sunbathing helps synthesize vitamin D. Adequate sunlight can help the body synthesize vitamin D on its own, while excessive sun protection can affect this process. What kind of sunlight intensity can help synthesize vitamin D? Professor Xie Zhongjian, director of the Institute of Metabolism and Endocrinology at Central South University, explained that in daily life, we can judge by looking at the length of our own shadow under sunlight. If the shadow is longer than one's height, it means that the ultraviolet intensity in the sunlight is not enough. If it is shorter than one's height, the ultraviolet intensity in the sunlight is sufficient. At the same time, the public can also obtain vitamin D from high-fat fish and other foods in the ocean with high vitamin D content. For people with insufficient sunlight exposure, vitamin D supplements can also be used, including different oral dosage forms such as 400 units, 800 units, 5000 units, and can also be supplemented by intramuscular injection of vitamin D preparations. Simply supplementing calcium is not enough to address osteoporosis. Li Mei, Deputy Director of the Endocrinology Department at Peking Union Medical College Hospital, stated that in terms of treatment, in addition to calcium and vitamin D being very important therapeutic cornerstones, multiple drugs can also be combined for treatment. For example, estrogen replacement therapy, the use of drugs such as bisphosphonates and denosumab to inhibit bone loss, drugs such as parathyroid hormone analogs to promote bone formation, and dual acting drugs. (New Society)