Calcium is the most abundant mineral in the human body. Almost all calcium is stored in the bones and teeth. Only about 1% of the calcium in your body is in the blood, muscles and the fluid between your cells. Calcium is needed for strong bones and teeth, plus it plays an important role in normal blood clotting, muscle contraction, hormonal secretion and nervous system function.
Source: Calcium Fact Sheet – National Institutes for Health
Calcium is found in dairy products such as milk, cheese and yogurt. You’ll also find calcium in dark green vegetables, whole sardines and calcium fortified foods such as breakfast cereal and some brands of orange juice. Your body also needs plenty of vitamin D in order to absorb and use calcium.
Your body constantly breaks down and rebuilds your bones to keep them strong. When you're young, your body builds up calcium as fast as it removed it from the bone, that’s why it’s so important for kids to get enough calcium from a healthy diet. When you get older, your body tends to resorb more calcium than it puts back so you're at a greater risk for osteoporosis. Calcium supplements are often recommended for women to help prevent osteoporosis. They’re generally safe and readily available over the counter, but supplements of any kind shouldn’t be used in place of healthy food sources of vitamins and minerals.