My opinion is that mercola.com is a junk science site that wants to sell you
its own products.

Calcium citrate is a fine way of getting calcium, but it is not inexpensive.
The amount of calcium per pill is lower than ordinary calcium carbonate pills.
These work just as well in almost everybody (except possibly seniors who have
lowered stomach acid). Get a good cheap source and don't worry.

Vitamin D is easy to get from many sources, including ordinary multivitamin
tablets and many other foods. Again, only seniors really need to worry about
having vitamin D in their calcium in the winter and that's only if there is no
other source of the vitamin in their diets. If you want to take a pill with
vitamin D all the time, that should be fine, however.

I have links to several better sources of calcium information on my Links
page:
http://ourworld.compuserve.com/homepages/stevecarper/links.htm

Steve Carper
Steve Carper's Lactose Intolerance Clearinghouse
http://ourworld.compuserve.com/homepages/stevecarper