TAKING CALCIUM SUPPLEMENTS - THE RIGHT WAY!

It is well-known that women should take calcium supplements daily. However, when and how you take your calcium will play a major part in how effective it'll be. Calcium supplements should ideally be taken on an empty stomach (except in the elderly who should take their calcium with meals) and should not be taken along with sources of iron, caffeine or fibre, as all these may inhibit calcium's optimal absorption.

Therefore, taking your calcium with your high fibre breakfast cereal and morning coffee is not advisable. Also, if you have been advised to take more than 1 tablet a day, take 1 in the morning and 1 in the evening - rather than the 2 together - to ensure that it is properly absorbed. 

http://all4women.co.za/health/daily-health-tips/other-health-tips/calcium-supplements.html