list the risks of calcium(Ca) for our health.

Answer 1

Since this is not my area of expertise, I searched Google under the key words "calcium health risks" to get these possible sources:

https://www.google.com/search?client=safari&rls=en&q=calcium+health+risks&ie=UTF-8&oe=UTF-8&gws_rd=ssl

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

http://www.hackcollege.com/blog/2011/11/23/infographic-get-more-out-of-google.html