Answer :Bess Dawson-Hughes, MD, director of Tufts HNRCA Bone Metabolism Laboratory, says it depends on bioavailability-the degree to which a nutrient, such as calcium, can actually be utilized by the body when its ingested-and the type of food being fortified. “In many cases the bioavailability of calcium added to foods has been studied and shown to be adequate,” she explains. “To the extent that the calcium is known to be bioavailable and that the foods that are fortified are nutritious, which is often the case, then these fortified foods would be preferred over supplements to bring total calcium intake up to the RDA. Consumption of non-nutritious foods and beverages to which calcium has been added, such as cola drinks, candy or other sweets, is not recommended.”
For adults, the Recommended Dietary Allowance for calcium is 1,000 milligrams a day for ages 19 through 50; 1,000 milligrams per day for men ages 51 through 70; 1,200 milligrams a day for women ages 51 through 70; and 1,200 milligrams per day for all adults ages 71 and older.