In a perfect world, we'd get all the calcium we need from the foods we eat. Not just the usual suspects like yogurt, milk, and cheese, but also canned salmon and sardines, broccoli, kale and collard greens, and fortified cereals and juices. But we live in an imperfect world.
Research suggests that more than a third of us aren't getting enough of the mineral that's essential for building and maintaining strong bones. It helps muscles work and nerves carry messages between the brain and other parts of the body, too.