The good news is that osteoporosis is largely preventable by taking four steps. No single step alone prevents the disease. Inadequate calcium intake contributes to the development of osteoporosis, and many girls and women consume less calcium than recommended to maintain healthy bones. Depending on age, an appropriate calcium intake is between 1,000 and 1,300 mg a day. You can increase dietary calcium by eating calcium-rich foods such as milk, cheese, broccoli, etc.
Vitamin D is necessary for the body to absorb calcium from food in the intestine.
Apart from building bone, your body needs calcium for other purposes such as allowing the heart, muscles and nerves to function properly. If you are not absorbing enough calcium from food your body takes the calcium it needs from your bones. As we age the ability to make vitamin D in the skin decreases. It is recommended that we take 400 to 800 international units of vitamin D daily. Major food sources of vitamin D are fortified dairy products, egg yolks, saltwater fish and liver.