Even though you are diligent about eating a balanced diet, you can still be calcium deficient. Coral Calcium is a very popular alternative to add calcium to your diet. Coral Calcium may be the best calcium supplement out there. Coral calcium is a great source of calcium for your body. This is because it is able to be absorbed by the body more easily than regular calcium. While other calcium supplements may be well known, it is more important that your body absorbs the proper amount of calcium.