At present, the overwhelming advertising campaigns in various media have made “osteoporosis” a popular term, and we seem to have suddenly realized that osteoporosis is closely related to our health. But most people still don’t understand: why do we suffer from osteoporosis? In fact, osteoporosis is not a disease, just like high blood pressure is not a disease, they are just a pathological phenomenon or state, and only when osteoporosis reaches strict medical standards and scales, it is considered a disease, that is, osteoporosis. Osteoporosis has a very appropriate expression inside the English language: poor bone. As the name implies, poor bone means poor bone mass. The amount of bone our bodies have is like the amount of wealth we have, it can increase or decrease. When our wealth is lacking to a certain extent, we become poor; similarly, when our bone mass decreases to a prescribed standard, it will bring harm to our body and doctors will diagnose us with osteoporosis and become a real patient. For our bone mass to decrease to such an extent depends on two factors: the high peak bone mass and the rate of bone loss. What is peak bone mass? It is also the highest bone mass value in a person’s lifetime, at the age of 35 for women and 40 for men, after which bone mass starts to decrease year by year. Peak bone mass is our family’s wealth, so we can see the significance of calcium supplementation during fetal life, infancy and early childhood, as well as encouraging physical activity in adolescents! Each person’s peak bone mass is determined by genetics, but it can be optimized through acquired efforts. Once the peak bone mass is completed, it is a matter of how to prevent the rapid loss of bone mass. The bones throughout our body are in a constant metabolic cycle, which is what makes organic life different from inorganic matter. On the one hand, new bone is constantly being produced (anabolism), and on the other hand, some of the bone is absorbed and broken down (catabolism), which allows the bones to constantly adjust themselves to the needs of the body and to repair damaged bones. There are two factors that affect bone metabolism: external factors are the action of mechanical forces and internal factors are the action of various hormones in the body. Our bones will increase in bone mass and bone strength after repeated external forces, and in the opposite case, if we do not exercise or even brake for a long time, we will lose bone mass and lose bone strength. The hormones that affect bone metabolism in the body include vitamin D, sex hormones, parathyroid hormone, thyroxine, growth hormone, corticosteroids, etc. The hormones most closely related to primary osteoporosis are sex hormones and vitamin D. Estrogen is the most important of these hormones, as one-third of a woman’s bone mass is related to and maintained by estrogen, which means that a deficiency of estrogen will cause a loss of this part of the bone mass. This means that a deficiency of estrogen will cause a loss of bone mass. This is one of the reasons why estrogen needs to be supplemented in a timely manner after menopause. Of course, women can rest assured that the estrogen used in clinical practice is quite safe and has a very low chance of causing cancer in female reproductive organs, but it has a very good protective effect on bones. Androgens and bones are not as closely related as estrogen, and men do not have the same sudden decrease in sex hormones as women, so androgens are rarely used to treat osteoporosis in men. Vitamin D can promote intestinal calcium absorption and bone formation, and elderly people will be affected by vitamin D deficiency in bone metabolism, so osteoporosis in elderly people should pay attention to vitamin D supplementation. At this point, people not only ask, “Why is the impact of “calcium deficiency” not mentioned when so many factors causing osteoporosis are mentioned? In fact, this is what the media and people are more concerned about, but calcium is only one of the nutrients in the body, no one has said that osteoporosis is a malnutrition disease, we can only say that calcium is one of the necessary nutrients to maintain normal bone metabolism. Osteoporosis is like a “thief” that steals our bones unknowingly, slowly approaching our body under the influence of lack of exercise, poor nutrition, estrogen deficiency, bad habits, drugs and diseases. Of course, we can prevent these “thieves” from stealing our bones and avoid the occurrence of osteoporosis, which requires us to increase outdoor activities, more sunshine, reasonable diet (pay attention to vitamin D and calcium supplementation), estrogen supplementation, quit smoking, limit alcohol, and actively treat the primary disease. As long as there are techniques to prevent “thieves”, we can stay away from osteoporosis and make our bones strong!