Coral Calcium or Multi Supplements.

For a long time many have claimed that supplements were unnecessary and a waste of money.
There has been some truth in that since more than 50% of supplements recently tested, failed to disintegrate properly. Many popular supplements scored less that ten out of one hundred, based on a comprehensive set of test criteria.

There seems to be a growing acknowledgement that we are no longer receiving all the nutrients we need, with facts like the following being published.
"10 million Americans have osteoporosis and another 34 million have low bone mass caused by calcium deficiencies."
On the other hand there are people in other parts of the world who consume less calcium, and yet have no osteoporosis. So there must be other factors involved.

Another area that appears to be finding consensus is that it is preferable to take a balance of supplements, rather than one or two in isolation.