Not Convinced That Calcium Is a Nutrient That Most People Are Depleted In? Then Read:

The Calcium Factor: The Scientific Secret of Health and Youth
by Robert R. Barefoot & Carl J. Reich, M.D.:
http://www.amazon.com/Calcium-Factor-Scientific-Secret-Health/dp/0963370324

Robert R. Barefoot's website:
http://www.barefootscureamerica.com/