A Government Panel called "The U.S Preventative Services Task Force", Stated that taking 400 IU of Vitamin D and 1000 mg of Calcium carbonate supplements did not prevent Bone fractures in older women and that they may actually harm them by increasing the risk of kidney stones.
This Government panel is either being funded by a big Pharmaceutical company or they are really uneducated in the field of Nutritional Science.
First of all
Older people tend to have a weaker digestion so you would not give them Calcium Carbonate. Calcium Carbonate is difficult for people to digest and absorb when they have weak stomach acid.
Calcium Malate, Coral Calcium, hydroxyapatite, and Calcium Citrate are alot easier to absorb.
Second of all
Vitamin D is not the only vitamin that is needed to build healthy bones. Magnesium, Boron, Silica, Strontium, Vitamin K, are also some of the other important minerals and vitamins needed to create healthy Bones.
Kidney stones can sometimes be created when calcium is not absorbed from the blood stream and they end up in the kidneys as "stones" This happens when you dont absorb calcium ....This occurs for many reasons, the major being you dont have the right vitamins and minerals needed to store away that calcium into your bones.
If you use a more absorbable form of Calcium along with the other required Vitamins and minerals in the right amounts
you should be able to build strong Bones.
The Best Calcium Supplement that I have found is
"Daily Bone Xcel"click on banner below