Calcium tablets should be taken after meals, not before meals, it is best to take half an hour after meals or with food. If you eat calcium tablets before meals, it is easy to form calcium carbonate in the body, the stomach in order to digest these calcium carbonate will secrete a large amount of gastric acid, a large amount of gastric acid for a long time will cause discomfort, aggravate the burden on the stomach and intestines, but also on the stomach to cause damage. Calcium tablets can only be broken down into calcium ions that can be absorbed by the body under the action of gastric acid. If you take calcium tablets half an hour after a meal, the body will secrete enough gastric acid, and the absorption of calcium tablets will be better, and it will not stimulate the intestines and stomach too much, and it will not cause constipation. If consumed with food, avoid food containing too much oxalic acid to reduce the absorption of calcium tablets, the best time to take calcium tablets is still at night before going to bed.