It takes a lot of vegetables to supply the body's daily need of calcium which is about 1000 mg per day for most people. Milk and other dairy products are the best natural sources of obtaining calcium in the diet. Many are fortified with vitamin D which increases the body's uptake of calcium. Skim milk and lo-fat cheeses and yogurt are the best for overall health. Calcium supplements are what are notoriously bad at providing calcium to the body. A large percentage of what is found in the pills passes straight through the digestive system without being absorbed. They are, however, starting to offer calcium-vitamin D combo supplements that do better.