Thorne's Calcium, as DiCalcium Malate, with 250 mg per capsule, is more concentrated than other forms of calcium (such as calcium carbonate), and is absorbed significantly better than calcium carbonate.* Those individuals most at risk for inadequate calcium intake are: Peri-menopausal and post-menopausal women* Women with irregular menstruation, particularly women in which this is due to prolonged athletic activity or strenuous military service* Individuals on a dairy-free diet* Vegetarians and vegans, because their diets are higher in plant-derived phytates and oxalates that inhibit calcium absorption* Pregnant women, particularly women with a history of gestational hypertension* Individuals on prescription and OTC medications such as antacids (H2 blockers or proton pump inhibitors) that can inhibit absorption, or glucocorticoids such as prednisone that can increase calcium loss* Individuals with a vitamin D deficiency – because vitamin D is necessary for calcium absorption*