Research indicates that a large proportion of the U.S. adult population does not consume the 1,300 mg of calcium the U.S. Food and Drug Administration recommends for daily dietary intake. Individuals who are at the most risk for calcium inadequacy because of decreased intake, disordered metabolism, decreased absorption, increased loss, or increased need include peri- and postmenopausal women, vegans, individuals who take certain prescription and OTC medications, and those with a vitamin D deficiency (because vitamin D is necessary for calcium absorption).* Thorne's Calcium, 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.*