Calcium is vital to the human body, not only for bone health, but also may be related to hypertension and PMS. 99% of calcium in the body is deposited in the bones, and calcium supplementation is the most basic measure to prevent and treat osteoporosis. The recommended daily intake of elemental calcium by the Chinese Nutrition Society is 800 mg for adults and 1000 mg for postmenopausal women and the elderly, however, the average daily intake of elemental calcium from the diet of the elderly in China is only about 400 mg, therefore, additional calcium supplementation is needed. However, when people are faced with many calcium supplements, they often find it difficult to choose. Some claim to have a high calcium content, while others say they are well absorbed, so people really don’t know what to do. First of all, before taking calcium supplements, you should have a checkup to understand the blood and urine calcium levels, such as blood calcium, urine calcium/creatinine ratio, bone metabolism-related hormones, and kidney ultrasound, which are very important for deciding which calcium to take and how much calcium to take. Therefore, before taking calcium supplements, you should go to a specialist clinic in a hospital for examination and consult a specialist for information on how to take calcium supplements appropriately. 2, the safest and most economical calcium supplement is still from food, among which, the food with high calcium content and good absorption is the first dairy, such as cow’s milk contains 120 mg of elemental calcium per 100 ml, can drink 250 ml of milk every day can get 300 mg of elemental calcium, milk also contains a variety of amino acids, lactic acid, minerals and vitamins, to promote the digestion and absorption of calcium. Moreover, the calcium in milk is more easily absorbed by the body, therefore, milk should be used as the main food for daily calcium supplementation. Other dairy products such as yogurt, cheese and milk flakes are good sources of calcium, followed by eggs, especially egg yolks with high calcium content, and other products like soy products, hard fruit foods (such as peanuts and walnuts), seafood such as shrimp skin, shrimp, kelp, nori, fish pine and meat pine made from spiny bones, and vegetables such as goldenrod, radish, shiitake mushroom and fungus all have high calcium content. Animal bones such as pig bones, chicken bones and other calcium content is very high, but difficult to dissolve in water, unless in boiling bone soup with some vinegar, can make a small amount of calcium dissolved in the bones to the bone soup, only some calcium supplement effect. General grain such as rice, noodles, corn in the calcium content are less, not as the main source of calcium. 3, the choice of calcium supplements whether “liquid calcium” or “calcium capsules” is better? In fact, the choice of calcium supplements should pay more attention to the elemental calcium content, different calcium salts contain different elemental calcium, commonly used calcium supplements, calcium hydrogen phosphate contains 23% of elemental calcium, calcium gluconate contains 9% of elemental calcium, calcium carbonate elemental calcium content is relatively high, up to 40%, is currently the most widely used and cost-effective calcium supplements. The absorption of calcium has a great relationship with the amount of calcium required by the human body and the amount of calcium supplementation. Generally speaking, the absorption rate of calcium in the human body is 10-30%, infants, pregnant women and lactating mothers need more calcium and have a higher absorption of calcium. However, the total calcium intake of human body should not exceed 2000 mg per day, otherwise it is likely to bring side effects, such as kidney stones, soft tissue calcification, etc. 4, calcium supplements are best taken between meals, generally plant foods contain more lipids and oxalic acid, and lipids and oxalic acid can be combined with calcium ions into insoluble calcium salts, which can not be used by the body and excreted. Animal food contains a lot of fat, and too much fatty acid can be combined with calcium ions, also affect the body’s use of calcium. For these two reasons, taking calcium supplements at mealtime can cause the body to waste calcium by reducing its absorption rate, so only taking calcium supplements between meals can ensure that calcium is better utilized. But for people who lack stomach acid in taking some calcium preparations will feel upset stomach, then you can choose to take after meals to reduce the stimulation of the stomach. 5, calcium absorption requires the participation of vitamin D. Vitamin D is a faithful partner of calcium and can promote intestinal calcium absorption. Without the participation of vitamin D, the body’s absorption of dietary calcium does not reach 10%. In addition, vitamin D also has the function of promoting the reabsorption of calcium by the kidneys and regulating blood calcium levels. The source of vitamin D in the body is from dietary intake, the second is through the sun’s ultraviolet radiation skin synthesis, vitamin D and then through the liver and kidney enzyme activation, become active vitamin D. People rarely go outdoors in winter, the amount of skin synthesis of vitamin D reduced, so should be supplemented in the right amount to enable the body to maximize the absorption of calcium, which is particularly important for the elderly. 6. During the process of calcium supplementation, it is also necessary to pay attention to follow-up visits to the hospital’s specialist clinic to monitor blood calcium, urine calcium levels and changes in hormones related to bone metabolism, and to adjust the calcium supplementation program. It is generally recommended to go to the hospital every 3-6 months for check-ups and adjust the calcium supplementation program according to the test results. In conclusion, patients with osteoporosis should undergo a reasonable examination before calcium supplementation, formulate a reasonable calcium supplementation plan, and conduct regular specialist follow-up to achieve the goal of safe calcium supplementation.