2, calcium carbonate is inorganic calcium, characterized by high calcium content per tablet, but the solubility of the absorption rate is low, because it is calcium carbonate, the absorption of gastric acid needs to be involved in the gastrointestinal tract disorders of the patient, may be belching, constipation, bloating, gastrointestinal flatulence, nausea, vomiting, and so on, the occurrence of adverse reactions, and there are a small number of possible hypercalcemia.

3, calcium citrate is a kind of organic calcium, calcium organic acid absorption rate and bioavailability is significantly higher than inorganic calcium, because it does not require the participation of gastric acid, the gastrointestinal tract irritation is also less.

4, for renal insufficiency, high blood calcium patients are cautious, the choice of different calcium varieties need to be based on the patient's specific situation.