The first brand is Ao Bai Calcium, which is a health care product produced in the United States. Moreover, the raw materials used in this health care product are all high-quality pure natural plant extracts, which will not cause any stimulation and harm to the body. When taking it, it will take some time to have obvious effects. For middle-aged and elderly people, it is necessary to take calcium produced by this brand to improve the occurrence of diseases in middle-aged and elderly people. The second brand is Jian 'anxi calcium tablets, which is also a health care product brand produced in the United States. At the same time, this brand ranks among the best in global sales, and this brand. After taking it, it can effectively strengthen bones, enhance the absorption and strength of calcium and enhance bone density. The third brand is Preston calcium brand, which is the largest health care product company in the United States. It produces calcium and supplements calcium, vitamins and minerals needed by human body in time. For women, taking this product can also play a role in losing weight and beautifying. These are about American brands of calcium tablets. Now we know that we should buy through formal channels to ensure product quality.